WO2009056093A1

WO2009056093A1 - Device for pulling a material web off a power loom and power loom comprising such a device

Info

Publication number: WO2009056093A1
Application number: PCT/DE2008/001689
Authority: WO
Inventors: Manuel Renz
Original assignee: Lindauer Dornier Gesellschaft Mbh
Priority date: 2007-10-29
Filing date: 2008-10-16
Publication date: 2009-05-07
Also published as: DE102007051526B3

Abstract

On a power loom, the draw-in roller (2) for pulling off the material web (1) is supported at the ends in machine stands (15). The material web (1) wraps around the draw-in roller (2) with an angle of contact in the required dimension in that it is guided via deflection rollers (12a, 12b, and 12c) and via a pressure roller (3) adjustably by way of a pressure force. The pressure roller (3) is supported at the ends in pivot levers (10). A tension members (4), which is flexible in some regions and is attached to a toggle lever (7) by means of a loose roller (8), engages on each pivot lever (10). By pivoting the toggle lever (7), the tension member (4) is tensioned and the pressure roller (3) is pulled against the draw-in roller (2). Adjustable compression springs (5) bring about the contact pressure of the pressure roller, while helical compression springs (6), which are supported on the stops (13) fixed onto the machine, are only used to hold the pivot levers and consequently the pressure roller (3) in the position away from the draw-in roller (2).

Description

DEVICE FOR REMOVING THE TRACK ON A WEB AND WEB MACHINE WITH SUCH A DEVICE

The invention relates to a device for removing the web on a weaving machine, with a driven for rotation Einziehwalze and at least one pressure roller whose longitudinal and rotational axis is parallel to the Einziehwalze and adjustable by means of an adjusting device between an operating position and an open position, wherein the pressure roller is set in the operating position under pressure in the direction of the drawing roller and in the open position of this moved away, and wherein the device is designed such that during operation of the weaving machine, the web under zonal wrap of draw-in roller and pressure roller between them passed and to the draw-in roller is pressed, according to the preamble of claim 1.

Such a device is known from DE-A-20 15 369. In this known device, two pressure rollers are employed against the drawing-in roller. The running of the shed fabric is characterized by a large wrap on the drawing-in and is led to the fabric tree. The two pressure rollers are mounted at their ends in pivot levers whose pivot axes are above the Einziehwalze. The two pressure rollers thus depend on the pivot axes of their pivot arms and fall by their weight in the direction of the drawing roller down. The pressure exerted by the nip rollers during operation on the web thus results from the weight of the nip rolls and their pivot arms as well as from extending in the longitudinal direction of the web tension of the web.

If in the device according to DE-A-20 15 369 the beginning of a new web to be wrapped around the draw-in roller, the two pressure rollers are pivoted each by itself on their pivoting levers upwards and locked in the raised position by pawls. The only roller is then freely accessible for insertion of the new web. In DE-A-20 15 639 there are no indications of a device with which the pivot levers of the pressure rollers could be raised. It must therefore be assumed that the two pressure rollers must be brought individually by hand in the raised position. This handling is cumbersome and requires a lot of effort. In addition, the known device has the disadvantage that the Contact pressure of the two pressure rollers can not be adjusted, at least not independent of the longitudinal tension in the web.

Also in the device for removing the web according to EP-A2-14 89 212 of the feed roller two pressure rollers are assigned, which are mounted in pivot levers. The contact pressure with which the pressure rollers are employed in the direction of the drawing-in roller is hereby produced by tension springs which act on the ends of the pivot levers. The pressure rollers are thus basically pulled by the tension springs in their operating position. To transfer the pressure rollers in the open position, a special adjusting device is provided. It consists of two interconnected two-armed levers that engage the pivot levers of the first pressure roller. The pivot lever of the first pressure roller are rotationally connected via cams or gears with the pivot levers of the second pressure roller. When depressing the interconnected two-armed lever, the pivot levers of the first pressure roller are pivoted away from the Einziehwalze, and the pivot lever of the second pressure roller perform this movement also, because they are rotationally coupled to the pivot levers of the first pressure roller. In this pivotal movement of all the pivot lever, the clamping force of the two tension springs must be overcome, and it is also necessary to reliably secure the two-armed lever in the open position against the clamping force of the tension springs. The known device according to the

EP-A2-14 89 212 is thus constructed relatively expensive; a particular disadvantage is that for the transition to the open position the tension springs must be stretched even further than is necessary for the operating position; the operation thus requires a considerable effort.

In contrast, the invention is based on the object, a device of the type mentioned in such a way that with simple and reliable construction of the contact pressure of the pressure rollers adjustable and the operation is facilitated.

) The solution of this object is achieved according to the invention with the entirety of the features of claim 1. In a device according to the preamble of claim 1 is thus provided according to the invention that at the ends of the pressure roller tension members are provided which are flexible at least over part of their length and cooperate with elastic return members, wherein the return members, the pressure roller in the Hold open position and transfer the tension members against the restoring force of the return members in the operating position upon actuation of the adjusting device, the pressure roller.

By moving the pressure roller in the device according to the invention via tension members, which belong to the adjusting device and are designed to be flexible at least over part of their length, there are advantageous constructional possibilities to gently tension these tension members. Further, elastic return members such as springs are provided, which hold the pressure roller in the open position; the return members are thus loaded in the open position solely by the weight of the pressure roller, whereby no special safety device for maintaining the open position is required. Only when the tensioning roller is transferred from its open position to the operating position by the tensioning of the tension members and thus a clamping force is effective anyway, the return members are also stretched, but they counteract the necessary for the application of the contact pressure clamping force. The device according to the invention is thus basically simple in construction and safe to operate without excessive force.

According to a first advantageous embodiment, it is provided that the ends of the pressure roller are mounted in pivot levers which are pivotable about housing-fixed articulation points and on which attack both the elastic return members and the tension members.

The device according to the invention is easily adjustable in that the tension members engage with the interposition of a tensioning and balancing spring at the ends of the pressure roller or the pivot levers, wherein in the open position of the pressure roller both the i elastic return members and the tensioning and balancing springs are substantially unstressed , Alone by the choice of spring constants for the tensioning and balancing springs of the contact pressure of the pressure rollers can be adjusted.

A further improvement results from the fact that the tensioning and compensating spring is a) adjustable pressure spring.

Since in the device according to the invention tension members, which are designed to be flexible over at least part of their length, as part of the adjusting device cause the change between operating position and open position, according to a further embodiment i results in an advantage in the use of two pressure rollers. It can namely at each end the two pressure rollers, the tension members are combined to form a single tension member with a common actuator. The tension member may for example be formed into a loop, wherein only a single tensioning device is required to tension the tension member and to pivot two pivot levers at the same time.

Claim 6 indicates an advantageous embodiment of a device with two pressure rollers, wherein the following features are provided at each end of the two pressure rollers:

a) The end of the pressure roller is mounted in a respective pivot lever;

b) it is provided for both pivot lever common tension member which is flexible at least in its central region;

c) the tension member forms a loop and engages with its first end portion on the first pivot lever and with its second end portion on the second

Swivel lever on;

d) the elastic return members are formed as helical compression springs, which are clamped between the pivot levers and fixed to the housing stops;

e) in its middle, the loop forming area, the tension member is operatively connected to a tensioning device, in the actuation of the two pivot levers are pivoted against the restoring force of the helical compression springs in the Anpressstellung.

Further advantageous details of this device are specified in the further subclaims. Particularly noteworthy is the formation of the tensioning device in the form of a toggle lever, which passes the tension member moved to a loop when tensioning over the dead center of its maximum extent.

Claim 11, finally, is directed to a loom, in accordance with the invention, a device for removing the web according to claims 1 to 10 is provided.

The invention will be explained in more detail with reference to embodiments which are illustrated in the drawings. In detail, the figures show the following: Fig. 1 shows a side view of the first embodiment of a device according to the invention with a single pressure roller, which is in its open position.

FIG. 2 is a side view corresponding to FIG. 1, but with the pressure roller in its operating position.

Fig. 3 shows the side view of a second embodiment of the invention, in which two pressure rollers are provided, which are shown in their open position.

Fig. 4 is a side view corresponding to Fig. 3, but with the two pressure rollers are in their operating position.

In Fig. 1, the inside of a machine stand 15 can be seen, which belongs to a loom and in which a driven drawing-in roller 2 is mounted. The drawing-in roller 2 extends in its longitudinal direction perpendicular to the plane of the drawing and with its opposite end towards the observer. At this end, another machine stand of mirror-image, but otherwise the same training is provided. The feed roller 2 can be driven by an intermediate gear from the main drive of the loom or have its own drive.

Between the two machine stands 15 a web 1 is withdrawn; in the illustration of Fig. 1, the web 1 runs from right to left. It runs successively over a first deflection roller 12a, the drawing-in roller 2, a pressure roller 3, then via a second deflection roller 12b and a third deflection roller 12c. From the third guide roller 12c to the web 1 is no longer shown. It continues to run in a known manner on a cloth, not shown, and is wound there with adjustable tension.

The guide of the web 1 shown in Figures 1 and 2 by the guide rollers 12a, 12b and 12c and by the pressure roller 3 causes the web 1 is guided around the Einziehwalze 2 with a very large wrap angle of more than 270 °.

^' The pressure roller 3 is freely rotatably mounted at its ends in two pivot levers 10, of which in Figs. 1 and 2 naturally only one can be seen. The pivot point of the pivot lever 10 is formed as a pivot axis 18; each pivot lever 10 indicates his the pivot axis 18 opposite end also on an actuating lug 19. According to Figures 1 and 2, the pivot axis 18 of the pivot lever 10 is arranged such that a running in the longitudinal direction of the web 1 tension increases the contact pressure of the pressure roller 3 on the drawing-in roller 2. The pivot axis 18 could also be arranged so that the tension of the web 1 does not affect the contact pressure. Then it is possible to adjust the pressing force of the pressure roller 3, regardless of the amount of tension in the web 1.

In the following, the adjusting device for pivoting the pivot lever 10 will be described. Since such an adjusting device is present on each side of the drawing-in roller 2, although the two actuating devices are mirror-inverted but otherwise identical, only the device visible in FIGS. 1 and 2 is described.

By the actuating lug 19 of the pivot lever 10 of the first end portion 4 a of a tension member 4 is movably passed, which must be flexible at least in its central region and there runs over a freely rotatable support roller 16. The tension member may be formed as steel cable, steel band, chain or the like. The first end portion 4a engages via an adjustable compression spring 5 on the actuating lug 19 of the pivot lever 10. The adjustable compression spring 5 is designed as a helical spring and is tensioned by means of a nut 11, which is screwed onto the first end portion 4 a of the tension member 4. The adjustable compression spring 5 is effective between the nut 11 and the actuating lug 19.

Next, a helical compression spring 6 is provided, which is also pushed onto the first end portion 4 a of the tension member 4. The helical compression spring 6 is located between the actuating lug 19 and a machine-fixed stop 13 of the machine stand. If a tensile force in the direction downwards is exerted on the tension member 4, both the adjustable compression spring 5 and the helical compression spring 6 must be compressed so that the pressure roller 3 is transferred from its open position according to FIG. 1 into the operating position according to FIG.

With its second end portion 4b, the tension member 4 is fixed to a roller 8 which is loosely mounted on the end of a toggle lever 7. The toggle lever 7 is pivoted for actuation about its pivot axis 9, and the rotation axis 17 of the loose roller 8 is eccentric to the pivot axis 9 of the toggle lever 7. As is clear from the comparison of Figures 1 and 2, the axis of rotation 17 is passed over a dead center when the toggle lever 7 out of his Position according to FIG. 1 (open position) in its position shown in FIG. 2 (operating position) is transferred. By the pivoting of the toggle lever 7 from its position shown in FIG. 1 in the position shown in FIG. 2, the distance of the axis of rotation 17 is increased by the machine-fixed stop 13. In this case, first, the helical compression spring 6 is compressed until the pressure roller 3 rests on the web 1 on the drawing-in roller 2. Upon further pivoting of the pivot lever 10 down the adjustable compression spring 5 is compressed, and the pressure roller 3 is applied to the Einziehwalze 2 with the desired contact force. The toggle lever 7 has a stable position in the operating position, because it is pulled by the tension of the adjustable compression spring 5 and the helical compression spring 6 against the toggle lever stop 14.

The adjustable compression spring 5 and the helical compression spring 6 act on the actuating lug 19 of the clamping lever 10 together, but in the opposite direction. The helical compression spring 6 is supported on the machine-fixed stop 13 and holds the pressure roller 3 in its open position in which it is lifted from the drawing-in roller 2; The helical compression spring 6 only has to compensate for the proportionate weight of the pressure roller 3. The adjustable compression spring 5, however, causes in the operating position the tension of the tension member 4 and thus the contact force with which the pressure roller 3 is pressed against the drawing-in roller 2. The spring constant of the adjustable compression spring 5 is therefore greater by a multiple than that of the helical compression spring. 6

There are several ways to adjust the contact pressure of the adjustable compression spring 5. For this purpose, first a compression spring 5 can be selected with a certain spring constant; when choosing a coil spring and a certain spring characteristic, namely progressive or degressive behavior is selectable; Furthermore, the bias can be adjusted by means of the nut 11, and finally, the contact pressure can also be influenced by the effective tensile length of the tension member 4.

FIGS. 3 and 4 show the second embodiment of the device i according to the invention. Here, the drawing-in roller 22 are associated with two pressure rollers 23a and 23b. The structure of the device remains basically the same as it has already been explained for the device with only one pressure roller 3 with reference to Figures 1 and 2. For the first orientation, it should be noted that in the embodiment according to FIGS. 3 and 4, a second pressure roller 23a is arranged approximately at the point at which the second deflection roller 12b is located in the first embodiment according to FIGS. Therefore The embodiment according to FIGS. 3 and 4 need not be described in detail. By contrast, the components already described in FIGS. 1 and 2 in FIGS. 3 and 4 are provided with reference numerals increased by the number 20, that is to say, material web 21 instead of web 1. An exact reference numeral list is also to be found at the end of the description. In the following, therefore, only the details of Figures 3 and 4 will be explained, which relate to the arrangement of two pressure rollers 23a, 23b and their operation.

In the illustration according to FIGS. 3 and 4, the material web 21 runs from right to left in this order over the first deflecting roller 32a, the drawing-in roller 22, the first pressure roller 23a, the second pressure roller 23b and the further deflecting roller 32b. In this way it is again achieved that the web 21 rests against the drawing-in roller 22 with a large wrap angle of more than 270 °. Furthermore, a mechanical longitudinal tension in the material web 21 has the effect that the material web 21 reinforces the contact pressure force on the draw-in roller 22.

Both pressure rollers 23a, 23b are pivotably mounted in pivoting levers 30a, 30b, wherein the associated pivot axes 38a, 38b are located in the interior or intermediate space between the pressure rollers 23a, 23b. Each pivot lever 30a, 30b has on its side opposite to the) pivot axis 38a, 38b, ie outside, an actuating projection 39a, 39b, on which the end portions 24a, 24b of a tension member 24 engage.

The tension member 24 forms in its central region a loop 24 c, which is guided over the loose roller 28 of the bell crank 27. In addition, the tension member 24 bears against the support roller 36. On

5 each end portion 24a, 24b of the tension member 24 is a helical compression spring 26a, 26b pushed, which is supported on a housing-fixed stop 33a, 33b. The end portions 24a, 24b are connected to the actuating lugs 39a, 39b of the pivot levers 30a, 30b, so that the pivot levers 39a, 39b can exert a pulling action on the end portions 24a, 24b and vice versa the tension member 24 with its end portions 24a, 24b the pivot levers

D 30a, 30b can pull down on the actuating lugs 39a, 39b.

3, the two helical compression springs 26a, 26b lift the pivoting levers 30a, 30b, and the pressure rollers 23a, 23b are lifted from the drawing-in roller 22. The helical compression springs 26a, 26b are thereby compressed only by the proportionate weight of the pressure rollers 23a, 23b. But if the tension member 24th is tensioned by the toggle lever 27, as has already been described with reference to Figures 1 and 2, the helical compression springs 26a, 26b must be compressed until the pressure rollers 23a, 23b abut on the web 21 on the drawing-in roller 22, cf. Fig. 4. Upon further tensioning of the tension member 24 only the adjustable compression spring 25 of the pressure rollers 23a, 23b is compressed until the operating position and thus the desired preset contact pressure is reached.

The adjustable compression spring 25 is provided only at one of the two end portions 24a, 24b of the tension member 24; in the present case this is the first end region 24a. Since the tension member 24 forms a loop 24c, which is connected via the loose roller 28 with the knee lever 27, a single adjustable compression spring 25 is sufficient to ensure a force balance between the first pressure roller 23a and the second pressure roller 23b, so that both pressure rollers 23a, 23b press the fabric web 21 against the surface of the draw-in roller 22 with the same contact force.

Thus, in the embodiment according to FIGS. 3 and 4, the particular advantage is achieved that by pressing only one pair of toggle levers 27, two pressure rollers 23a, 23b are set against the retraction roller 22 or lifted off it.

In both embodiments described naturally on each side of the pressure rollers 3, 23a, 23b depending on a toggle lever 7, 27 are adjusted when one or two pressure rollers 3, 23a, 23b to be transferred from the open position to the operating position or vice versa. As long as the amount by which the pressure rollers 3, 23a, 23b are to be lifted off the drawing-in roller 2, 22 is not too great, the toggle levers 7, 27 can even be actuated sequentially on both sides of the rollers. The bearings on both sides of each pressure roller 3, 23a, 23b namely have enough clearance, so that a temporary slight inclination of the pressure rollers 3, 23a, 23b is harmless when lifting or lowering. However, if the pressure rollers 3, 23a, 23b are to be lifted by larger amounts, it may be necessary to synchronize the movement of the two toggle levers 7, 27 with one another. For this purpose, both sides of the device can be connected to each other, for example by a cable.

Claims

claims

1. A device for removing the web on a weaving machine, with a driven for rotation of the drawing roller and at least one pressure roller whose longitudinal and rotational axis parallel to the drawing roller and is adjustable by means of an adjusting device between an operating position and an open position, wherein the pressure roller is set in the operating position under pressure in the ^• direction of the draw-in and moved away in the open position of the latter and wherein the device is designed such that during operation of the weaving machine, the web under partial wrapping of draw-in roller and pressure roller between them passed and to the drawing-in roller is at the ends of the pressure roller (3, 23a, 23b) tension members (4; 24a, 24b) are provided which are flexible at least over part of their length and cooperate with elastic return members, the Rückstellglie the pressure roller (3; 23a, 23b) in the open position hold and the tension members (4, 24a, 24b) on actuation of the adjusting device, the pressure roller (3, 23a, 23b) against the restoring force of the return members in the operating position.

2. Device according to claim 1, characterized in that the ends of the pressure roller (3; 23a, 23b) in pivot levers (10; 30a, 30b) are mounted, which are pivotable about housing-fixed pivot points and where both the elastic return members and the Tensile elements (4, 24a, 24b) attack.

3. Device according to claim 1 or 2, characterized in that the tension members (4; 24a, 24b) with the interposition of a tensioning and compensating spring at the ends of the pressure roller (3; 23a, 23b) or the pivot levers (10; 30a, 30b In the open position of the pressure roller (3, 23a, 23b), both the elastic restoring members and the tensioning and compensating springs are essentially unstressed.

4. Device according to claim 3, characterized in that the tensioning and compensating spring is an adjustable compression spring (5, 25).

5. Device according to one of claims 1 to 4 with two pressure rollers, characterized in that at each end of the two pressure rollers (23 a, 23 b) the Tension members are combined to form a single tension member (23a, 23b) with a common adjusting device.

6. Device according to claim 5 with two pressure rollers, characterized in that at each end of the two pressure rollers (23a, 23b), the following features are provided:

a) the end of the pressure roller (23a, 23b) is mounted in a respective pivot lever (30a, 30b);

b) there is provided a tension member (24) which is common to both pivoting levers (30a, 30b) and which is flexible at least in its central region;

c) the tension member (24) forms a loop (24c) and engages with its first end portion (24a) on the first pivot lever (30a) and with its second end portion (24b) on the second pivot lever (30b);

d) the elastic return members are formed as helical compression springs (26a, 26b) which are clamped between the pivot levers (30a, 30b) and fixed stops (33a, 33b);

e) in its middle, the loop (24c) forming the tension member (24) is operatively connected to a tensioning device, in the actuation of the two pivot levers (30a, 30b) against the restoring force of the helical compression springs (26a, 26b) pivoted into the Anpressstellung become.

7. Device according to claim 6, characterized in that the clamping device in the form of a toggle lever (7) is formed, which passes the tension member (24) during clamping over the dead center of its maximum extent.

8. Device according to claim 7, characterized in that the tension member (24) on the toggle lever (7) on a loose roller (28) is guided.

9. Device according to one of claims 6 to 8, characterized in that the rigidly executed end portions (24b, 24c) of the common tension member (24) by the helical compression springs (26a, 26b) are passed.

10. Device according to one of claims 6 to 9, characterized in that only at one of the two pivot levers (30a, 30b) an intermediate clamping and compensating spring in the form of an adjustable compression spring (25) is provided.

11. Weaving machine with a device for removing the web according to one of claims 1 to 10.