WO2006032361A1

WO2006032361A1 - Drawing gear for spinning machines

Info

Publication number: WO2006032361A1
Application number: PCT/EP2005/009579
Authority: WO
Inventors: Gernot SCHÄFFLER
Original assignee: Maschinenfabrik Rieter Ag
Priority date: 2004-09-22
Filing date: 2005-09-07
Publication date: 2006-03-30
Also published as: JP2008513615A; CN101027435A; EP1791993A1; DE102004047581A1; WO2006032361A8

Abstract

The invention relates to a drawing gear for spinning machines in which the feed roller pair (3,4) may be adjusted to match the preliminary draft field to differing staple lengths. Several ratchet levels (20,20A,20B,20C) are provided for adjustment of the lower roller (3), for each of which two corresponding ratchet levels (21,22,21A,22A,21B, 22B,21C,22C) for the upper roller (4) are provided. The corresponding ratchet levels for the upper roller fix two different lines of application (X,X2) for the tensioning spring (24), whereby the one line of application (X1) runs at a given separation (A) in front of the axis (11) of the lower roller (3) and the other line of application (X2) runs at the same separation (A) behind the axis (11) of the lower roller. The upper roller thus has a constant advance or retard with relation to the lower roller, whereupon the tension of the pensioning spring remains constant in all adjustment positions.

Description

Drafting system for spinning machines

The invention relates to a drafting system for spinning machines with at least one pair of clamping rollers, which consists of a driven lower roller and a compression spring pressed against the upper roller, both longitudinally adjustable paths and parallel to each other in the direction of distortion of the fiber structure are adjustable so that the line of action of the loading spring not through the axis of the lower roller runs.

A drafting system of this kind is state of the art by EP 0 370 190 B1. In this known drafting system, both the lower roller and the upper roller of each pinch roller pair can be adjusted continuously. The lower rollers are for this purpose on continuously adjustable slide, the top rollers with the aid of a gauge in longitudinal slots of the upper rollers supporting load carrier displaceable.

The individual consisting of lower rollers and upper rollers pinch roller pairs are therefore adjustable so that an adaptation to the fiber material to be processed can be made. In many cases, this adaptation to the staple length of the fiber material is limited to the input roller pair of the drafting system. Thus, as a rule, only the first pair of pinch rollers is adjusted, as a result of which the length of the first draft zone of the drafting system, the so-called pre-draft zone, changes. The remaining pairs of nip rollers usually remain in their position. Although not disclosed in the cited document, it is known to those skilled in the art that the top roller of the pinch roller pair with respect to the associated lower roller should have a certain curtain or back. This means that the line of action of the loading roller loading the top roller should not run through the axis of the lower roller. This prevents the axes of the top roller and the bottom roller from being able to tilt at an angle to each other. A non-parallelism of the two axes would be the Deteriorate the drafting process of the drafting system. The said curtain or back of the upper roller with respect to the lower roller should, of course, be maintained even with an adjustment of the pinch roller pair.

In compliance with this requirement, there is now the problem that the curtain or back, so the distance between the lines of action of the loading spring from the axis of the lower roller, not always remains the same. This inevitably leads to variable spring travel of the loading spring. In conventional ring spinning this is of minor importance, because due to relatively flat spring characteristics, the load forces change little. However, the situation is different with high-draft drafting systems, in particular when a sliver initially placed in a sliver can be submitted to an air-jet unit after being stretched. In such a case, even slight differences in spring travel already mean greater spring forces and thus different warping forces, which would impair the reproducibility of a spinning process. It is therefore necessary to reset the load springs each time in such a case.

The invention is based on the object at a drafting arrangement of the type mentioned different spring travel of the loading spring and thereby avoid different warping forces.

The object is achieved in that a plurality of latching steps are provided for adjusting the lower roller, which are associated with two corresponding latching steps of the top roller, the corresponding latching steps define two different lines of action for the loading spring, of which the line of action at a predetermined distance in front of the axis the lower roller and the other line of action run at an equal distance behind the axis of the lower roller.

Instead of a continuous adjustment of the lower roller and the upper roller, the nip roller pair is now adjusted according to the invention in individual predetermined stages, the number of which is arbitrary. Due to the fixed assignment of the latching steps and the corresponding latching steps to each other, the distance of the lines of action of the loading spring to the axis of the lower roller always remains the same, ie one works with a constant curtain or rear of the upper roller with respect to the lower roller. This leads to constant spring travel and thus constant clamping forces, which at a Adjusting the distance between two adjacent pairs of pinch rollers readjusting the load springs is no longer necessary.

Advantageously, the latching stages assigned to the lower roller have equal distances from one another. For example, four detent stages may be provided for the pre-draft zone, wherein the distances between two adjacent detent stages may be in the range of two to five millimeters.

Suitably, the distances of the corresponding latching steps can correspond to each other half the distance of the lower roller associated latching steps. Thus, the distances of the upper roller associated with corresponding latching steps are all the same size.

Further advantages and features of the invention will become apparent from the following description of an embodiment.

Show it:

1 is a partially sectioned side view of a drafting system according to the invention,

FIG. 2 shows in a reduced representation the explanation of the meaning of a curtain or back of a top roller;

FIG. 3 is an enlarged view of an adjustable pair of pinch rollers for explaining differently sized curtains or backsides;

FIG. 4 shows a representation corresponding to FIG. 3 with constant curtains and back hangers according to the invention,

FIG. 5 shows a further enlargement and a schematic representation of the arrangement of the latching steps and of the corresponding latching steps relative to one another,

Figure 6 in a reduced view again a front view of an adjustable in detent stages drafting. A drafting system 1 according to Figure 1 for spinning machines is upstream of a subsequent air jet unit 2 in the present case. In such air spinning machines different delay forces of a drafting system 1 are particularly critical.

The drafting system 1 is designed as a three-cylinder drafting system and contains successively referred to as Klemrhwalzenpäar input roller pair 3, 4, then as Riemchenwalzenpaar 5, 6 with Führungsriemchen 7, 8 formed middle pair of rollers and a final, referred to as pair of delivery roller pair output rollers 9, 10th The rollers 3, 5 and 9 are driven lower rollers, in the rollers 4, 6 and 10 formed as pressure rollers upper rollers. The upper rollers 4, 6 and 10 associated load springs are indicated in Figure 1 only as spring forces X, Y and Z. The associated lines of action of these loading springs are denoted by x, y and z.

As can be seen, the lines of action x, y and z do not extend through the axes 11, 12 and 13 of the associated lower rollers 3, 5 and 9. As a result, the respective upper rollers 4, 6 and 10 with respect to their associated lower rollers 3, 5 and 9 a small so-called curtain or backhang. As a result, the position of the axes of mutually associated pinch roller pairs in their parallelism is stabilized.

By means of the drafting system 1, presented as a sliver or roving fiber structure 14 is warped in accordance with the direction of delay A to a desired fineness. Following the Lieferwälzenpaär 9, 10 of the drafting 1 is then a finished stretched thin Fasefbändchen 15, which should receive its spin rotation in the air jet unit 2.

To adapt to different staple lengths of the fiber structure 14 to be spinned, the nip roller pair 3, 4 is adjustable in its distance from the Riemchenwalzenpaar 5, 6. In this case, there is a straight adjustment path B-C for the lower roller 3, for the upper roller 4 a parallel, likewise straight adjustment path D-E. Dash-dotted in Figure 1, an adjusted pinch roller pair 3a, 4a indicated. In such an adjustment process, it is provided that the line of action x does not continue to pass through the axis 11 of the lower roller 3.

The meaning of the curtain or rear of the upper roller 4 with respect to the lower roller 3 will now be explained with reference to the reduced FIG. 2. This is shown by an example in which two adjacent top rollers 4 and 19 are connected by a common axle 16 and combined to form a so-called twin pressure roller centered in one Load carrier 17 is supported. In such a case, the lower roller 3 may extend over a plurality of spinning stations. It is expressly understood, however, that of course a single bottom roll 3 and a single top roll 4 can form a nip roll pair with each other.

As can be seen from Figure 2, the axis 16 of a top roller 4 or a pressure roller twin 4, 19 strives to be inclined according to the directions of the double arrow or in the opposite direction. This danger exists in particular when the line of action x of the spring force X passes through the axis 11 of the lower roller 3. The risk is reduced, however, if the line of action x is at a certain distance from the axis 11 of the lower roller 3, that is, if there is a certain curtain or rear of the upper roller 4 with respect to the lower roller 3. By a curtain or back the parallelism of the axes 11 of Uήterwalze 3 and the axis 16 of the upper roll 4 and the Druckwalzenzwillings 4, 19 stabilized to each other.

FIG. 3 shows a lower roller 3 with an associated upper roller 4, in which the spring force X of the associated loading spring has a line of action x, which has a certain distance ai from the axis 11 of the lower roller 3. If now - without the lower roller 3 to adjust - the upper roller 4 is moved to a dot-dash line position 4 ", then the contact line P between the lower roller 3 and the upper roller 4, in the present case to a contact line Q. It is here a spring force X "assumed, the line of action x" to the axis 11 of the lower roller 3 has a distance a ₂ , and it is basically irrelevant whether the distances ai and a ₂ each on the same side of the axis 11 or on different sides In any case, it can be seen from FIG. 3 that here the top roller 4 has a different curtain or rear position in its position 4 "than before an adjustment. This inevitably leads to a difference u in the spring travel of the loading spring arises. This difference u in the spring travel leads to different spring forces X and X. This in turn results in different warping forces along the contact line P or Q between the lower roller 3 and the upper roller 4. This is to be avoided according to the present invention.

The basic arrangement according to the invention will now be explained with reference to FIG. It can be seen again a lower roller 3, which is associated with a top roller 4, which in turn can be adjusted in a dot-dash line position 4 ', without moving the lower roller 3 in the direction of delay A. The two spring forces X ₁ and X ₂ here have lines of action X ₁ and X ₂ , each having an equal distance a from the axis 11 of the lower roller 3. Accordingly, there is no longer any spring path difference at the contact lines P ₁ and P ₂ . The spring forces X ₁ and X ₂ are thus the same before and after an adjustment of the curtain or back of the upper roller 4. According to a feature of the invention, it is thus provided that a top roller 4 has an always constant curtain or back with respect to the associated bottom roller 3. Each position of a lower roller 3 are thus associated with two fixed positions of the upper roller 4.

In other words, two lines of action X ₁ and X _{2 are} predetermined for the loading spring of a top roller 4, of which the one line of action X ₁ at a predetermined distance a in front of the axis 11 of the bottom roller 3 and the other line of action X ₂ at an equal distance a behind the axis 11 of the lower roller 3 extends.

The illustrated curtains and backs should also be maintained when the lower roller 3 is adjusted in the direction of delay A of the drafting system 1. From the purely schematic representation according to FIG. 5, it can be seen that three further positions 3a, 3b and 3c shown in dash-dotted lines can be provided for the lower roller 3. For this purpose, there are a total of four different latching steps 20, 20a, 20b and 20c, which remain at a distance b from each other. So you waived a stepless adjustability of the lower roller 3, but you can approach the state of a stepless adjustability largely by a sufficient smallness of the distance b. Corresponding to the different latching steps 20, 20a, 20b and 20c, there are also four different positions 11, 11a, 11b and 11c for the axis of the lower rollers 3.

From Figure 5 can be seen for the basic position of the lower roller 3, the two lines of contact P ₁ and P ₂ for the two fixed positions of the upper roller 4, not shown here. The two lines of contact P ₁ and P ₂ have a distance c from each other, which is half the distance b equivalent. The arrangement is now made so that not only the distances b, but also the distances c between each remain the same in all stepped adjustment positions. Although this is not absolutely necessary for the invention, it is very convenient. The individual adjustment positions of the upper roller 4, not shown in FIG. 5, correspond in total to eight corresponding latching steps 21 and 22, 21a and 22a, 21b and 22b as well as 21c and 22c. Of course, these eight latching steps 21 to 22c could also be arranged in a line next to each other, but this would be difficult because the distances c are only in a range of four to five millimeters. It will now be explained with reference to FIG. 6 how an adjustment element 23 of a load carrier can be adjusted with the aid of the aforementioned corresponding latching steps 21 to 22c. It can be seen from Figure 6, as arranged on the adjusting element 23 via a loading spring 24, a holder 25 which carries an axis 16 for a pair of printing rollers 4, 19. Of course, it is also possible here to provide drafting units 1 with individual upper rollers 4.

It can be seen on the adjusting element 23 lateral pin 26 and 27, which can be selectively inserted into the corresponding corresponding latching steps 21 to 22c. These latching steps 21 to 22c are fixedly mounted on the load carrier of the drafting system 1. On a positionally accurate alignment of the adjusting element 23 to the load carrier is not discussed here. Incidentally, in this FIG. 6, it is assumed that the corresponding reaming steps 21 to 22c are located next to one another in a row.

Claims

claims

1. drafting system (1) for spinning machines with at least one pair of clamping rollers (3,4), which consists of a driven lower roller (3) and by a loading spring (24) pressed against the upper roller (4), both longitudinally straight adjustment paths (BC, DE) and parallel to each other in the direction of delay (A) of the fiber structure (14) are adjustable so that the line of action (x) of the loading spring (24) does not pass through the axis (11) of the lower roller (3), characterized in that for adjusting the lower roller (3) a plurality of latching steps (20, 20a, 2öb, 20c) are provided, each associated with two corresponding latching steps (21, 22, 21a, 22a, 21b, 22b, 21c, 22c) of the upper roller (4) the corresponding latching steps (21, 22) define two different lines of action (xi, X ₂ ) for the loading spring (24), of which the one line of action (X ₁ ) at a predetermined distance (a) in front of the axis (11) of the lower roller ( 3) and the other line of action (x ₂ ) in an equal distance (a) behind the axis (11) of the lower roller (3).

2. drafting arrangement according to claim 1, characterized in that the lower roller (3) associated latching steps (20, 20a, 20b, 20c) have the same distances (b) from each other.

3. drafting system according to claim 2, characterized in that the distances (c) of the corresponding latching steps (21, 22; 21a, 22a; 21b, 22b; 21c, 22c) from each other half the distance (b) of the lower roller (3) associated Raststufen (20, 20a, 20b, 20c) correspond.