WO1997030201A1

WO1997030201A1 - Device for tensioning a warp thread sheet in a mechanical loom

Info

Publication number: WO1997030201A1
Application number: PCT/EP1997/000701
Authority: WO
Inventors: Henry Shaw; Arnold Moerman; Bart Lefever
Original assignee: Picanol N.V.
Priority date: 1996-02-17
Filing date: 1997-02-14
Publication date: 1997-08-21

Abstract

The invention concerns a device for tensioning a sheet of warp threads (19) in a mechanical loom, the tensioning device comprising a tensioning roller (16) which is supported at a plurality of locations over its length by support rollers (17, 18) arranged in two rows. The support rollers (18) in one row are arranged so as to yield in a resiliently elastic manner.

Description

Device for tensioning a warp thread sheet in a weaving machine

The invention relates to a device for tensioning a warp thread sheet in a weaving machine with a tensioning roller which extends over the width of the warp thread sheet and is supported several times over its length in a spring-elastic manner.

In a known device of the type mentioned at the outset (CS-A 163 601), the tensioning roller is arranged in shell-shaped receptacles of a plurality of holders which can be pivoted about axes running transversely to the tensioning roller. A rod which runs parallel to the tensioning roller and which is loaded by a spring engages on the holder which is designed as a two-armed lever.

It is also known (EP-B 0 109 472) to arrange on the machine frame of a weaving machine a plurality of end shields which are distributed over the width of the warp thread array and which accommodate a deflecting element, for example a deflecting roller. In these end shields, a hollow shaft is also rotatably supported as a supporting beam, to which a large number of connecting pieces are attached, each of which has a bearing shell with which a tensioning element is held, which, for example, can also be a tensioning roller. The invention has for its object to provide a simple construction for a device of the type mentioned, in which the moving masses can be kept low.

This object is achieved in that the tensioning roller is supported by means of a plurality of support rollers distributed over its length, which are arranged in two rows parallel to the tensioning roller, and in that the support rollers are resiliently held in at least one row.

In the embodiment of the device according to the invention, the moving masses are relatively small. The use of support rollers for supporting the tensioning roller has the advantage that the flat support of the tensioning roller on the support rollers is retained in every position.

In an embodiment of the invention it is provided that individual, resiliently arranged holders for the support rollers are connected to one another by means of one or more stiffening elements. This ensures that all holders move evenly in accordance with the load that occurs, so that the tensioning roller only moves in parallel positions.

In a further embodiment of the invention it is provided that the support rollers of the first row in the running direction of the warp yarn sheet are stationary and the support rollers of the second row in the running direction of the warp yarn sheet are arranged to be resilient. This enables a space-saving arrangement to be realized.

In a further embodiment of the invention it is provided that a common, resilient loading means is provided for several or all movable holders. This ensures provides that the loading forces on all holders are essentially the same.

In a further embodiment of the invention it is provided that the stationary support rollers are arranged in such a way that they absorb a larger proportion of the forces exerted by the warp thread group on the tensioning roller than the resiliently arranged support rollers. Since the elastically arranged support rollers only have to absorb a smaller proportion of the load forces that occur, the spring load forces can be kept correspondingly lower. This makes it possible for the tensioning roller to carry out relatively large movements in which the resilient loading forces change only relatively slightly, so that tension peaks in the warp thread family are avoided. The desired division of the forces exerted by the warp thread coulter onto the tensioning roller can be achieved in that the axes of rotation of the stationary support rollers with respect to an angle halve between the direction of feed of the warp thread coulter to the tensioning roller and the downward direction of the warp thread coulter from the tensioning roller in one are arranged at a smaller distance than the axes of rotation of the resilient support rollers.

In a further embodiment of the invention it is provided that the stationary support rollers have a diameter which is approximately the same size as or larger than the diameter of the tensioning roller. The diameter of the stationary support rollers determines the path of movement on which the tensioning roller moves. A large diameter of the support rollers enables the tensioning roller to move approximately in a straight line within the range of motion that occurs. In addition, a large diameter of the support rollers has the advantage that the rolling resistance of the tensioning roller with respect to these support rollers is relatively small. This is advantageous for avoiding tension peaks in the warp threads. In a further embodiment of the invention it is provided that a deflecting element for the warp thread sheet is arranged in the running direction of the warp thread sheet in front of the tensioning roller. This deflection element, which is arranged in a stationary manner, ensures that regardless of the diameter of a warp beam, the wrap angle of the warp thread family around the tensioning roller remains essentially the same.

In a further embodiment of the invention, it is provided that sealing elements are attached to the support tree, which extend over the width of the warp thread family and rest on the circumference of the tensioning roller. These sealing elements protect the area below, in which the support rollers and their holders are arranged, against weaving dust detaching from the warp thread coulter. Since the sealing elements lie against the tensioning roller, they also ensure that the tensioning roller is cleaned.

Further features and advantages of the invention result from the following description of the embodiments shown in the drawings:

1 shows a top view of a device according to the invention,

2 shows a section along the line II-II of FIG. 1 on a larger scale,

3 shows a section along the line III-III of FIG. 1 on a larger scale,

4 shows a plan view in the direction of arrow F4 on a section of FIG. 2,

5 shows a section corresponding to FIG. 3 with a different position of the tensioning roller, 6 shows a section similar to FIG. 2 of a modified embodiment,

7 is a plan view similar to FIG. 4 of a modified embodiment,

8 shows a section similar to FIG. 2 of a modified embodiment,

9 shows a section corresponding to FIG. 8 with a different setting of the resilient loading means,

10 shows a cross section of a further embodiment of a device according to the invention,

11 shows a section along the line XI-XI of FIG. 10,

12 shows a cross section through a further embodiment,

13 shows a section along the line XIII-XIII of FIG. 12,

14 shows a cross section of the embodiment according to FIGS. 12 and 13 with the changed position of the tensioning roller,

15 shows a cross section through an embodiment similar to FIG. 10 with loading means designed as air springs,

16 shows a cross section through an embodiment with linearly resiliently arranged holders,

17 shows a cross section through an embodiment similar to the embodiment according to FIGS. 10 and 11, wherein common support rollers are provided for a tensioning roller and a deflection roller, 18 shows a cross section through an embodiment similar to FIGS. 12 to 14, wherein holders for the elastically flexible supporting rollers are attached to stationary holders by means of one or more leaf springs,

19 shows an embodiment similar to FIG. 18, but with the leaf spring or leaf springs attached to a supporting tree,

20 shows a cross section through an embodiment in which the holders for the resiliently elastically arranged support rollers are attached to a common shaft,

Fig. 21 is a cross section of the embodiment of Fig. 20 with the changed position of the tension roller and

22 shows a section through an embodiment similar to FIGS. 20 and 21 with an additionally provided deflection roller.

1 shows the end regions of two side parts 1, 2 of a weaving machine, on which holding plates 3, 4 are height-adjustable and can be fixed in the set height position. The holding plates 3, 4 are attached, for example, in the manner known from US Pat. No. 5,293,908. The fastening means each contain an adjusting screw 5 and a fixing screw 6. Between the holding plates 3, 4 there is a supporting tree 7. The support tree 7 is a hollow profile. This hollow profile has a flat, essentially rectangular cross section. The support tree 7 can also be attached in a stationary manner to the frame of a weaving machine, for example by means of supports and / or intermediate beams. On the supporting tree 7, on the side facing away from the side parts 1, 2, a plurality of holders 8 are attached, which receive a deflecting element 8. As can be seen from FIG. 1, the holders 8 are arranged uniformly distributed over the width of the warp thread array 19, not shown in FIG. 1, which is shown in FIGS. 2 and 3. The holders 8 are fastened to the supporting tree 7 by means of screws 15, for example. The stationary 8 attached to the support tree 7 initially serve to receive a deflection element which is designed as a deflection roller 9. As can be seen in particular from FIGS. 2 and 3, the deflecting roller 9 is mounted radially and rotatably by means of support rollers 10, 11 arranged in two rows. The support rollers 10, 11 serve for the radial mounting of the deflection roller 9, which is held in the gap formed by the support rollers 10, 11 due to the tension of the warp thread array 19. The deflecting roller 9 is secured in the axial direction by means of two plates 12, 13 which are attached to the support tree 7. Holding elements 14 are attached to these plates 12, 13, which lie below the deflecting roller 9 and which support the deflecting roller 9 in the vertical direction in the absence of the tension of the warp thread array 19.

A tensioning element for the warp thread array 19 in the form of a tensioning roller 16 is mounted radially and rotatably by means of two rows of support rollers 17, 18, which form a gap for the tensioning roller 16. The deflecting roller 9 and the tensioning roller 16 run parallel and are at least the same length as a warp beam, not shown, from which the warp thread sheet 19 is pulled off. The support rollers 17 of the row facing the deflecting roller 9 are mounted in a stationary manner in the holders 8 already mentioned, which are fixed in a stationary manner on the supporting tree 7. In contrast, the support rollers 18 of the other row are mounted by means of resiliently arranged holders 20. As a result, the rotatably mounted tensioning roller 16 can move relative to the support rollers 17 and 18. This arrangement primarily ensures that the moving masses are reduced, since the support rollers 17 of the one row prevent the movement of the tensioning rollers. do not run ze 16. On the already mentioned plates 12, 13 there are further holding elements 29 which are arranged on the side facing away from the support rollers 18 close to the tensioning roller 16 and which have the task that the tensioning roller falls down in the absence of tension of the warp thread sheet 19 can.

The support rollers 18 are arranged in one or more holders 20 which are held in the form of a leaf spring 21 by means of loading means. One end of the leaf spring 21 is fastened by means of a screw 23 and a clamping piece 22 to the holders 20. The other end of the leaf spring 21 is held clamped by means of a screw 24 between a clamping piece 25 and a support 26 which is fastened to the supporting tree 7. As a result, the leaf spring 21 is arranged between the support tree 7 and the holders 20, i.e. more precisely between the support 26 and the holders 20, as a result of which the holders 20 are arranged flexibly. The leaf springs 21 are designed and arranged relative to the tensioning roller 16 in such a way that they form a pivot axis for the holders 20 which runs essentially parallel to the tensioning roller 16. In order to be able to adjust the tension of the leaf spring 21, a stop 27 is provided in the support 26, which can be adjusted by means of an adjusting means in the form of a screw 28 in order to change the spring action of the leaf spring 21.

As shown in FIG. 4, two support rollers 17 for the tensioning roller 16 are arranged on each of the holders 8, which have the same diameter and which are arranged coaxially to one another. The two support rollers 17 are arranged on the outer sides of these holders 8. The support rollers 10 and 11 are also arranged in these holders 8. They are located between the collars of these holders 8. The supports 26 for the support rollers 18 are at a safe distance from the holders 8. The support rollers 17 and 18 are therefore not opposed to one another. 4 also shows that the stop 27 can be adjusted in height by means of the screw 28, which is provided in the region of the outer sides of this stop 27. The attachment of the leaf springs 21 to separate supports 26 is advantageous for the attachment of the leaf spring 21 and the adjustment of the stop 27. This arrangement also allows the leaf spring 21 to run approximately through the center of the axis of rotation of the support rollers 17, whereby the Support rollers 18 can be arranged such that the tension roller 16, as will be described in more detail later, can be in a position according to FIGS. 3 and 5. The support rollers 10, 11 and 17 are rotatably supported by means of axes arranged in the holders 8. The support roller 18 is mounted by means of an axis which is arranged in the holders 20 which are connected to the supports 26 by means of the leaf spring 21 and the clamping piece 22. The axes are arranged parallel to the support tree 7. As can be seen, the support rollers 10, 11 and 18 have a shape in which the axial length is significantly larger than the diameter, while the support rollers 17 have a relatively large diameter, while the axial length is smaller than the diameter.

As can be seen from FIGS. 2 and 5, the support rollers 17 of the stationary row have a diameter which is substantially larger than the diameter of the tensioning roller 16. The diameter of the tensioning roller 16 is also substantially larger than the diameter of the support rollers 18 of the elastically flexible row, so that, in addition, the diameter of the support rollers 17 of the stationary row is significantly larger than the diameter of the support rollers 18 of the elastically flexible row. The large diameter of the support rollers 17 means that the tensioning roller 16 can move over a relatively large distance on the support rollers 17 with approximately linear movement. This is not only advantageous for the movement of the tensioning roller 16 along a predetermined path, but is also advantageous in that relatively soft leaf springs 21 can be used by the tension peaks in the warp thread array 19 can be largely avoided.

As can be seen from FIG. 3, the tensioning roller 16 is arranged such that the bisector 31 between the direction of the warp thread sheet 19 running to the tensioning roller 16 and the direction of the warp thread sheet running away from the tensioning roller 16 between the axes of rotation of the support rollers 17 and 18 lies. This bisector 31 lies close to the connecting line from the axis of rotation of the tensioning roller 16 to the axis of rotation of the support rollers 17 with the large diameter. This also means that the angle A between the bisector 31 and the connecting line from the axis of rotation of the tension roller 16 and to the axis of rotation of the support rollers 17 is relatively small and much smaller than the angle C between the bisector 31 and the connecting line of the axis of rotation of the tensioning roller 16 to the axis of rotation of the support rollers 18. This arrangement ensures that the support rollers 17, which are mounted in the stationary holders 8, absorb the largest proportion of the forces exerted by the warp thread array 19 on the tensioning roller 16 during operation. The force F which the warp thread coulter 19 exerts on the tensioning roller 16 extends essentially along the bisector 31 between the axes of rotation of the support rollers 17 and 18, so that the tensioning roller 16 in the gaps between the support rollers 17 and 18 can be held. Due to the friction between the support rollers 17 and 18 and their axes on which they are mounted, the force F does not run exactly along the bisector 31, but these deviations are negligibly small, so that the force F is approximately along the bisector which 31 can be adopted on an ongoing basis.

As can be seen from FIG. 3, the force F is passed on as the force F17 which the tensioning roller 16 exerts on the support rollers 17 and as the force F18 which the tensioning roller 16 exerts on the support rollers 18. This arrangement has the advantage that the greatest proportion of the force F is exerted by the support rollers 17. is taken, and that the support rollers 18, which are mounted in the resiliently resiliently arranged holders 20, only have to absorb a small proportion of this force F. Since these holders 20 only have to absorb a small force, the advantage is obtained that these holders 20 can be held with relatively soft leaf springs 21 and can therefore be arranged in a relatively soft manner. The leaf spring 21 is also attached in the illustrated embodiment such that when the leaf spring 21 exerts little or no force on the tensioning roller 16 and when the warp thread coulter 19 exerts a force on the tensioning roller 16, this force is always present between the axes of rotation of the support rollers 17 and 18 and therefore the tension roller 16 is always loaded towards the support rollers 18 and not in the direction of the deflection roller 9. For this purpose, the limiting elements 29 can also be attached to a suitable location.

It is known that during weaving the tension in the warp thread sheet 19 and thus also the force with which the warp thread sheet 19 acts on the tensioning roller 16 vary between a minimum and a maximum value. This causes shed formation means, not shown, and sling means, not shown, which act on the warp thread array 19. If the tension in the warp threads is small and the force exerted by the warp thread family 19 on the tension roller 16 is small, the tension roller 16 is, for example, in a position as shown in FIG. 3. With a maximum tension in the warp threads, at which the force exerted by the warp thread sheet 19 on the tension roller 16 is maximum, the tension roller 16 is, for example, in a position as shown in FIG. 5. For this purpose, the spring stiffness of the leaf springs 21 is selected such that during weaving the tension roller 16 moves, for example, between the positions shown in FIGS. 3 and 5 and the leaf springs 21 load the tension roller 16 in the direction of the warp thread array 19. Due to the movement of the clamping Roll 16 is achieved that the tension in the warp 19 is at least approximately equalized.

As can be seen from FIG. 5, the force F18 which the support rollers 18 have to absorb is greater when the tensioning roller 16 is in the position according to FIG. 3. This force is greater not only because the force exerted by the warp thread sheet 19 on the tensioning roller 16 is greater, but also because the angle B between the bisector 31 and the connecting line from the axis of rotation of the tensioning roller 16 and the axis of rotation of the support rollers 17 is greater. Because of the large diameter of the support rollers 17, the increase in the angle B when the tension roller 16 is displaced about the support rollers 17 is relatively small. The angle B is also always smaller than the angle D between the bisector 31 and the connecting line from the axis of rotation of the tensioning roller 16 to the axis of rotation of the support rollers 18. The force exerted by the leaf springs 21 on the support rollers 18 is also greater. since the leaf springs 21 are deformed more. This creates a balance of forces. It is further evident that the stiffness of the leaf springs 21 must be selected such that the force exerted by the leaf springs 21 on the support rollers 18 is always sufficient to counteract the force with which the warp thread coulter 19 acts over the Tension roller 16 acts on the support rollers 18.

In order to avoid grinding the warp thread sheet 19 on the tensioning roller 16, the tensioning roller 16 is rotatably arranged on the circumference of the support rollers 17, 18. Because of the rotation of the tension roller 16, the warp threads of the warp thread sheet 19 can roll on the tension roller 16 during weaving. It is also understandable that the tensioning roller 16 is twisted by the warp threads during weaving and in the process mainly moves in the direction of the edge of the fabric, since the warp threads move in the direction of the edge of the fabric in order to be interwoven. In the illustrated embodiment, the tension roller 16 is made hollow. The support rollers 17 and 18 are made, for example made of a light, wear-resistant plastic. The tensioning roller 16 can be made both from steel and from a light, wear-resistant plastic. Because the tensioning roller 16 is supported several times, it can also have a small diameter without bending significantly in its longitudinal direction. Due to the aforementioned shape, the tension roller 16, the support rollers 17 and 18 form a small inert mass. The warp threads can due to the rotation of the support rollers 17 and 18 without a significant adverse influence of the inertia on the tension roller

16 run. The rotation is not hindered due to the friction of the support rollers 17 and 18 to their axes. Since the support rollers 17, which absorb the greatest proportion of the forces, have a relatively large diameter and in particular the diameter is larger than the diameter of the tensioning roller 16, the support rollers 17 only rotate over a small angle when the tensioning roller rotates 16, so that the influence of this friction is negligible. The diameter of the support rollers 17 is only limited by the installation space of the support rollers 17, which is present between the support beam 7 and the warp thread sheet 19.

The support rollers 17 and 18, which can be made of plastic, are rotatable about axes provided in the holders 8, 20, which are made of steel, for example. The plastic is selected so that the coefficient of friction between this plastic and steel is as low as possible.

In order to reduce the mass of inertia of the support rollers 17 with a large diameter, recesses (not shown) which extend over the width of the support rollers and which are approximately radially in the middle of these support rollers can be provided

17 are arranged.

The support rollers 10 and 11 can also be made of plastic. Since the deflection roller 9 is stationary during weaving remains arranged and since the deflecting roller 9 essentially rotates in the direction of the edge of the goods, the friction of the support rollers 10 and 11 is less disadvantageous in their axes.

For example, leaf springs made of stainless steel are selected as leaf springs 21, which deform little under permanent load, which have good deformation resistance and which therefore have a long service life. Since the leaf springs 21 are uniformly moving components and due to their arrangement only have to absorb small forces, the dimensions of the leaf springs 21 can be relatively small. The leaf springs can have a relatively small width and a relatively small thickness, so that they also form only a small inert mass.

If relatively soft leaf springs 21 are used, in order to always be able to provide a balance of forces, it may be necessary to provide stops 30 with a curved shape, as shown in FIG. 6. In this embodiment, the rigidity of the leaf springs 21 increases when the leaf springs 21 are bent more because the leaf springs 21 are supported by the stops 30 over a greater length. The stops 30 are fastened to the supports 26 with screws 36. When using very soft leaf springs 21, it is advantageous to give these leaf springs 21 a greater pretension so that the force exerted by these leaf springs 21 on the support rollers 18 is greater. For this purpose, in the embodiment according to FIG. 6, a rotatable clamping element 33 is provided on the support 26, in which the leaf spring 21 is clamped by means of screws 34. The clamping element 33 can be set at a desired angle and fixed in the selected position by means of screws 35. The leaf spring 21 is thus preloaded with the clamping element 33 and the stop 30, as a result of which the leaf spring 21 can exert a greater force on the support rollers 18. By adjusting the preload it is too possible to set a middle position of the support rollers 18 which they take up during weaving.

Since the forces exerted by the warp thread sheet 19 on the tensioning roller 16 can be different over the width of the weaving machine, the leaf springs 21 of the individual holders 8 can be set differently in order to ensure that the tensioning roller 16 extends over its entire length moved by approximately the same paths. On the other hand, the tension of the leaf springs 21 of the individual holders 8 can be set differently in order to ensure that the tensioning roller 16 can move in different ways across the width of the weaving machine. This makes it possible to obtain the desired tension differences in the warp threads across the width of the weaving machine.

In the embodiment according to FIG. 6, the holders 20 are not attached to the leaf springs 21 by means of a clamping piece. The individual holders 20 are connected to at least one stiffening element 32 which extends across the width of the weaving machine. The leaf springs 21 are clamped between the holder 20 and the stiffening element 32, which is fastened to the holders 20 by means of screws 23. The stiffening element 32 ensures that all holders 20 with the support rollers 18 and thus also the tensioning roller 16 move in the same way and in the same way. The stiffening element 32 only has to absorb a part of the forces, since a large part of the forces exerted by the tensioning roller 16 on the support rollers 18 is introduced directly into the support tree 7 via the leaf springs 21. The stiffening element 32 serves solely to compensate for differences between the forces on the various support rollers 18 in order to move all the support rollers 18 in the same way. Since the forces themselves are small, the forces to be compensated are even smaller, so that the stiffening element 32 only has to be designed to absorb these small forces and can therefore achieve stiffening even with a low inertial mass. According to a modification, not shown, of the embodiment according to FIG. 6, the clamping element 33 is not firmly attached to the holder 26. Instead, the clamping element 33 is fixedly attached to the end of a torsion spring in the form of a torsion bar. The other end of the torsion spring can, for example, be fastened to the holder 8 in a desired angular position in a manner as described in US Pat. No. 4,240,471 or EP Pat. No. 109,472. The leaf spring 21 can then be biased by means of the torsion spring. By adjusting the torsion spring, the bias of the leaf spring 21 can also be adjusted. In this case, the load means for the support rollers 18 do not consist solely of the leaf spring 21, but also of the torsion spring, not shown.

In the embodiment according to FIG. 7, the support rollers 10, 11 and 17 and also the leaf springs 21 for the holders 20 of the support rollers 18 are provided on the holders 8. The holders 20 with the support rollers 18 are located between the two support rollers 17, which are arranged on the outer sides of the holder 8. A compact structure is thus achieved. In this embodiment, the support rollers 18 are mounted in a holder 20 which has the shape of a U-shaped bearing block which is fastened to a leaf spring 21 with screws 23 and a stiffening element 32. As in the embodiment according to FIG. 6, the stiffening element 32 extends over the entire width of the weaving machine, so that it interacts with all holders 20 for the support rollers 18. In addition, the arrangement of the support rollers 17 on the outer sides of the holder 8 makes it possible for the support rollers 17 and the support rollers 10 and / or 11 to overlap one another in the longitudinal direction of the support tree 7. In order to prevent the leaf spring 21 from coming into contact with the axes of the support rollers 17, the support rollers 17 are each supported, for example, with their own short axis which does not extend through the holder 8 into the position of the leaf spring 21. In the embodiment according to FIGS. 8 and 9, the support roller 17 is mounted on an axis 38, which is arranged in a holder 8 fastened to the supporting tree 7. A support 39 is additionally rotatably mounted on the axis 38. A leaf spring 21 for a support roller 18 is attached to the support 39 by means of a clamping piece 25 and a screw 24. The support roller 18 is attached to the leaf spring 21 according to the embodiment of FIG. 2. The leaf spring 21 is arranged approximately centrally in the extension of the axis 38. The stiffness of the leaf spring 21 is adjusted by means of a stop 40 which is attached to the support 39 in a height-adjustable manner by means of a screw 36. By rotating the support 39, for example from the position shown in FIG. 8 to the position shown in FIG. 9, it is possible to preload the leaf spring 21. The support 39 can be fastened to the holder 8 by means of fastening means at a predetermined angle. These fasteners consist, for example, of a screw 41 which extends through a slot 42 in the holder 8 and which interacts with a nut (not shown) in order to clamp the support 39 against the holder 8. In order to rotate the support 39, a screw mechanism can be provided. In the exemplary embodiment, this consists of a screw 43 which is arranged axially adjustable in a slot (not shown) of a collar 44 of the holder and which cooperates with a part (not shown) and provided with a thread which is fastened to the axis 45 which is rotatably arranged on the support 39. This embodiment allows a compact structure of the different elements and also allows the preload of the leaf springs 21 to be set in a simple manner.

The embodiment according to FIGS. 8 and 9 is used for example in the following way. After a warp thread sheet 19 has been provided, the support roller 16 is arranged in such a way that the forces which the warp thread sheet 19 exert on the tensioning roller 16 lie between the axes of rotation of the support rollers 17 and 18 runs. As already described above, the bisector 31 then runs between the axes of rotation of the support rollers 17, 18 and close to the axis of rotation of the support rollers 17 of the stationary row. The support 39 is then rotated about the axis 38, the tension in the warp thread sharp 19 being increased, the tensioning roller 16 remaining approximately in the same position, but the pretension in the leaf springs 21 being increased. The support 39 is then fixed to the holder 8 using the fastening means 41, 42. The screw mechanism 43, 45 only serves to facilitate the turning of the support 39. The biasing of the leaf springs 21 takes place, for example, when all the warp threads are in the warp thread family, which are then under a minimum tension. The tension in the warp threads is always increased because of the shaping of shed and because of the stop of weft threads, so that during weaving the force exerted by the tension roller 16 on the support rollers 17, 18 is always between the axes of rotation of the support rollers 17, 18 runs. This embodiment is not only advantageous in order to adjust the pretension of the leaf springs 21, but also to apply leaf springs 21 with very low spring stiffness, which can nevertheless exert the desired force on the support rollers 18 due to the pretension. This embodiment also allows the middle position of the tensioning roller 16 to be adjusted during weaving. This means that by rotating the supports 39, the support rollers 18 and the tensioning roller 16 are also moved, so that the position of the tensioning roller 16 is also dependent on the angular position of the support 39. By rotating the support 39 it is also possible to change the position of the tension roller 16 and thus also to influence the outermost and the middle position of the tension roller 16 during weaving. Depending on the warp tension with which weaving is to take place, a suitable position of the tensioning roller 16 can thus be selected. With a low warp tension, weaving should take place, for example, when the support 39 is in the position according to FIG. 8. With a high warp tension, for example, should be woven 9 when the support 39 is in the position shown in FIG.

In the embodiment according to FIGS. 1 to 9 it is not only achieved that the moving masses (inert masses) are small, but the operation of the device according to the invention is also improved if support rollers 17 with large diameters are used and an advantageous one Anord¬ tion of the tension roller 16 and the support rollers 17, 18 is set, by which a favorable force is achieved. This favorable force effect not only allows the use of relatively soft load means, i.e. For example, leaf springs 21, which allows a relatively large movement of the tension roller 16 around the support rollers 17, but is also advantageous with respect to the rolling of the warp threads on the tension roller 16, whereby tension peaks in the warp threads of a warp thread sheet 19 can be largely avoided.

In the embodiment according to FIGS. 10 and 11, a plurality of holders 54 are arranged on the support tree 7 and are arranged uniformly distributed over the width of the weaving machine or the width of the warp thread array 19 and accommodate a stationary deflection roller 9. The holders 54 are U-shaped. Your crossbar is attached to the supporting tree 7, for example by means of screws. The legs protrude from the support beam 7 and carry at their ends two essentially superimposed support rollers 55, 56, in which the deflection roller 9 carried by the warp thread assembly 19 is rotatably mounted. The support rollers 55, 56 have a cylindrical shape, i.e. their axial length is significantly larger than their diameter.

The tensioning roller 16 is also mounted radially in two rows of support rollers 57, 58, which also have a roller-like shape. The support rollers 57 of the row facing the deflection roller 9 are mounted stationary in the holders 54. The support rollers 58, however, are loaded in swivel brackets 59 gert, which are pivotable about the axes of the support rollers 57 of the other row. With this design, it is first achieved that the movable masses are also small, since the support rollers 57 in one row do not carry out the tensioning movement of the tensioning roller 16. In addition, it is achieved that the tensioning roller 16 is elastically flexible in a direction which is approximately in the bisector of the direction in which the warp thread sheet 19 runs towards the tensioning roller 16 and the direction in which the warp threading means sharp 19 runs off the tensioning roller. This leads to the advantage that even relatively small paths of the tension roller 16 away from the warp thread sheet 19 or in the direction of the warp thread sheet 19 lead to relatively large changes in the tension of the warp thread sheet 19. The masses which oscillate when the warp thread sheet 19 is tensioned and relaxed are therefore only required to travel relatively small distances, so that the risk of the occurrence of high tension peaks is further reduced.

In each case two adjacent swivel holders 59 located in the area of a holder 54 are connected to one another by means of the axes of the support rollers 57, 58. In addition, all swivel holders 59 are connected by means of a stiffening element which, in the exemplary embodiment, consists of a rod 60 running parallel to the swivel axis of the support rollers 57. The rod 60, which serves as a stiffening means and prevents independent movements of the swivel holder 59, is inserted through bores in the swivel holder 59. The relative position of the swivel holder 59 to the rod 60 is fixed by means of tensioning screws 61, which clamp the swivel holder 59 onto the rod 60.

The swivel holders 59 are loaded with resilient loading means which load the swivel holders 59 and thus the tensioning roller 16 in the direction of the warp thread family 19. The loading means contain leaf springs 62 on which the ends of the axes of the support rollers 58 of the swivel holders 59 rest. The axes of the support rollers 58 are provided with rollers 63 on which NEN the leaf springs 62 rest. The leaf springs 62 are held in clamping blocks 64 which are fastened to the supporting tree 7 by means of screws 65. The undersides of the leaf springs 62 lie between the clamping blocks 64 and the rollers 63 on stops 66 which are fastened to the supporting tree 7 in an adjustable and fixable manner in the longitudinal direction of the leaf springs 62. By changing the position of the stops 66 in the longitudinal direction of the leaf springs 62, the spring force with which the leaf springs 62 act on the tensioning roller 16 can thus be adjusted. In a modified embodiment, it is provided that the stops 66 are adjustable in height, whereby the spring force of the leaf springs 62 acting on the swivel holder 59 can also be adjusted.

Since the swivel holders 59 are connected to one another in such a way that they can only move together, the total force of the leaf springs 62 determines the force with which the tensioning roller 16 acts on the warp thread family 19. In practice, it will therefore suffice if only the forces of the leaf springs located in the region of the side edges of the warp thread sheet 19 are provided with adjustable stops 66 in order to specify the tension of the warp thread sheet 19 by means of the tensioning roller 16.

The basic structure of the exemplary embodiment according to FIGS. 12 to 14 corresponds to the exemplary embodiment according to FIGS. 10 and 11, so that reference is made to the description of the exemplary embodiment according to FIGS. 10 and 11 with respect to the same reference numerals. One difference is that the support rollers 58 are mounted in swivel holders 67, which cannot be swiveled coaxially to the axes of the support rollers 57, but rather are mounted with a swivel axis 68 which is preferably arranged at a distance below the support rollers 57. Due to the separate arrangement of the pivot axis 68 for the pivot holder 67, it is possible to match the direction of movement of the tensioning roller 16 even better to the bisector between the feed direction of the warp thread array 19 to the tensioning roller 16 and to approach the downward direction of the warp thread sheet 19 from the tension roller 16. As a comparison between FIGS. 12 and 14 shows, the distance between the two rows of support rollers 57, 58, which is denoted by A in FIG. 12 and B in FIG. 14, changes during pivoting movements of the pivot holder 67. This leads to the fact that the swivel holders 67 have to travel a smaller swivel path in comparison to the swivel holders 59 of the exemplary embodiment according to FIGS. 10 and 11 in order to enable the tensioning roller 16 to have the same clamping movement. The smaller pivoting path of the pivot holder 67 and the tube 69 serving as a stiffening element also means that their mass is less disruptive. In addition, the advantage is obtained that the spring travel of the leaf springs 62 is also smaller, corresponding to the smaller swivel travel of the swivel holder 67. In addition, as shown in FIG. 13, the pivot holders 67 are arranged outside the U-shaped holders 54. Furthermore, in the embodiment according to FIGS. 12 to 14 it is provided that the stop 78 extends over the full width of the weaving machine. The position of this stop 78, which is, for example, a bar, can thus be changed on both sides of the weaving machine, the loading forces of all the leaf springs 62 being set jointly.

The basic construction of the embodiment according to FIG. 15 corresponds to the embodiment according to FIGS. 10 and 11. It differs from this in the design of the spring-elastic loading means. In the embodiment according to FIG. 15, air springs 70 are provided, by means of which the tensioning roller 16 is loaded in the direction of the warp thread array 19. The air springs 70 are arranged, for example, between the holders 54 and the rod 60 serving as a stiffening element. They are connected in a manner not shown by means of a control valve to a compressed air source such that the level of the pressure can be changed. The force with which the tension roller 16 tensions the warp thread sheet 19 can thus be changed very simply by changing the compressed air supply to the air springs 70. Air springs can understandably also be used in a similar manner in all the other exemplary embodiments as resilient loading means which act either on the swivel holder or on the stiffening means. In the embodiment according to FIG. 15 it is further provided that the support rollers 55, 56 for the deflection roller 9 are not mounted directly in the holders 54. Rather, the support rollers 55, 56 are mounted in bearing blocks 77, which are adjustable and, in particular, height-adjustable on the holders 54. It is thus possible to align the support rollers 55, 56 with the deflecting roller 9 and also to change the position of the deflecting roller 9 relative to the tensioning roller 16.

In the embodiment according to FIG. 16, holders 71 for the tensioning roller 16, which are guided in a straight line, are provided on the holders 54 for the deflecting roller 9. The support rollers 57 of the row facing the deflecting roller 9 are arranged stationary in the holders 54. The support rollers 58 are held by linearly movable, resiliently flexible holders. Between the holders 54 and 71 springs 72 are arranged loading means, the spring force of which is adjustable in a manner not shown. The holders 71 are connected to one another by means of a profile 73. Instead of the rectangular profile 73 shown, a round profile or a hollow profile can also be provided.

The embodiment according to FIG. 17 corresponds in its basic structure to the embodiment according to FIGS. 10 and 11. However, a further simplification has been made in that a common row of support rollers 80 are arranged in the holders 54 which support both the deflection roller 9 and the tension roller 16. The tensioning roller 16 is supported radially by means of the stationary support rollers 80 and a further row of support rollers 58, which are mounted in two-part swivel holders 75, 76 which can be pivoted about the axes of the stationary support rollers 80. All second swivel holders 75, 76 are by means of a tube 74 trained stiffener connected to each other. This tube 74 is stretched between the two parts 75, 76 of the swivel holder, which are each connected to one another by at least one screw 61.

The embodiment according to FIG. 18 has a certain similarity to the embodiment according to FIGS. 12 to 14 with regard to the arrangement of the two rows of support rollers 57, 58 for the tensioning roller 16. Here, too, only the row of support rollers 58 is held resiliently resilient, the distance between the two rows of support rollers 57, 58 also being increased and decreased during a resilient movement. The support rollers 58 are mounted in bearing blocks 81 which are fastened to the stationary holder 54 by means of relatively short leaf springs 82. The bearing blocks 81 are connected to one another by means of a profile 83 which serves as a stiffening element and which is fastened to the bearing blocks 81 by means of screws 86. The leaf spring 82 is clamped with clamping elements 84, 85 in a bearing block 81 and the holder 54.

In a modified embodiment similar to FIG. 18, a one-piece leaf spring 82 is provided which extends essentially over the length of the tensioning element 16 and which connects all holders 54 to the bearing blocks 81. In this case, the leaf spring 82 also serves simultaneously as a stiffening element connecting the bearing blocks 81, so that the profile 83 of the embodiment according to FIG. 18 serving as stiffening element can be omitted.

19, two rows of support rollers 57, 58 are provided for the tensioning roller 16, of which the support rollers 57 are stationary in the holders 54. The support rollers 58 are arranged in bearing blocks 88 which are held directly by leaf springs 72 in accordance with the exemplary embodiment according to FIGS. 10 and 11 or 12 to 14. The ends of the leaf springs 72 are elements 84 attached to the bearing blocks 88. In the region of the ends of the leaf springs 72 facing the bearing blocks 88, a profile 87, which serves as a stiffening element and which connects all the leaf springs to one another, is attached to them.

In an embodiment modified from FIG. 19, instead of individual leaf springs 72, a leaf spring is provided which extends essentially over the axial length of the tensioning roller 16. In this case, the end of the plate-shaped leaf spring connected to the bearing blocks 88 already acts as a stiffening element, so that the profile 87 can be dispensed with.

In the embodiment according to FIGS. 20 and 21, a tension roller 16 is also provided for tensioning the warp thread family 19. The tensioning roller 16 is mounted by means of two rows of support rollers 57, 58, which are on both sides of a bisector between the direction in which the warp thread sheet 19 runs to the tensioning roller 16 and the direction in which the warp thread 19 from the tensioning roller 16 expires, are arranged. The support rollers 57 of one row are stationary in stationary holders 90 which are attached to a support tree 7 by means of screws 91. The support rollers 58 arranged in a second row in the running direction of the warp threads 19 are resiliently held. These support rollers 58 are mounted in holders 92 which are attached to a common shaft 93 which extends over the weaving machine width and runs parallel to the support roller 16. The shaft 93, which is designed as a hollow shaft, is pivotably mounted in a plurality of bearing blocks 94, which are arranged within the supporting tree 7. The shaft 93 is connected in a rotationally fixed manner to one or two torsion spring bars 95 which are arranged in its interior. The ends of the torsion spring bar or bars 95 are adjustable and, in the set position, can be fixed to the support boom 7 or to the holding plates 2, 3 in such a manner as is known from US Pat. No. 4,240,471. The shaft 93 transmits the loading force applied by one or two torsion spring bars 95 uniformly via the holders 92 and the support rollers 58 to the tensioning roller 16, so that these are of essentially the same size at all points where the support rollers 58 engage them Elasticity is loaded. In this embodiment, the setting of the loading force is particularly simple, since the loading force is achieved by adjusting the torsion spring bar (s) 95 simultaneously for all support rollers 58 distributed over the length of the tensioning roller 16. Since the loading forces are set outside the weaving width, it is also possible to set this loading force to a suitable value while the weaving machine is running.

As indicated in FIGS. 20 and 21, the tensioning roller moves during the compensating movement dependent on the warp thread tension on a circular path with respect to the axis of rotation of the stationary support rollers 57. Such a movement on a circular path around the stationary support rollers perform the tensioning rollers 16 in all other embodiments.

The embodiment according to FIG. 22 corresponds to the embodiment according to FIGS. 20 and 21 with regard to the mounting of the tensioning roller 16. However, the holder 90 is additionally provided with two rows of support rollers 10, 11, in which a deflection roller 9 is mounted, which is arranged in the running direction of the warp thread sheet 19 in front of the tension roller 16.

In the embodiment according to FIG. 22, a plate-shaped, preferably spring-elastic sealing means 97 is attached to the support beam 7 by means of a screw 96, which bridges the area between the tensioning roller 16 and the support beam 7 and rests elastically on the tensioning roller 16 from below below the warp thread array 19 . This sealing means 97 prevents dust or the like detached from the warp thread sheet 19. in the loading empire of the support rollers 58 falls down. In addition, the sealing means 97 has a certain cleaning effect with respect to the tensioning roller 16, since it abuts the circumferential surface slightly. The sealing means is supported from below by means of one or more strip-shaped spring plates 98 which are fastened to the supporting tree 7 by means of screws 99.

In all of the illustrated embodiments, the tensioning roller 16 executes its compensating movements on a circular path around the row of the stationary support rollers 17, 57. The outer shells of rolling bearings can easily be provided as support rollers, for example the outer shells of ball bearings, roller bearings or needle bearings or other rolling bearings. In a modified embodiment, the deflecting roller 9 is not supported by means of support rollers 10, 11 or 55, 56 arranged in two rows, but in bearing shells attached to the corresponding holders.

In the embodiments according to FIGS. 10 to 19 and also according to FIGS. 20 to 22, the moving masses are small. The tensioning roller 16 moves only over a relatively small path around the circumference of the stationary support rollers 57, this path running approximately along a bisector which runs between the direction in which the warp thread family 19 runs to the tensioning roller 16 and the Direction in which the warp thread 19 runs away from the tensioning roller. Despite the relatively small paths, tension peaks in the warp threads of the warp thread family 19 can be largely avoided.

In all embodiments, the mass of the tensioning roller 16 and the masses of the holder and stiffening elements moving with it are relatively small, so that the risk of voltage peaks occurring as a result is reduced. The stiffening elements do not absorb the full support force of the tensioning roller 16, but only the forces which are necessary to achieve the same movement of all holders. This allows their dimensions and thus their masses to be relative be kept low. In the exemplary embodiments according to FIGS. 10 to 22, the advantage is also realized that the direction of movement of the tension roller 16 lies approximately in the direction of the bisector between the feed direction of the warp thread sheet 19 to the tension roller 16 and the discharge direction. As a result, even relatively short paths of the tensioning roller 16 lead to relatively large changes in the warp thread tension, so that the movable masses do not have to travel long distances. This also makes it possible to further reduce the risk of occurrence of voltage peaks due to inertial forces, particularly at high working speeds.

It is particularly advantageous if the elements supporting the tensioning roller 16 themselves carry out only a relatively small movement, but in the process enable a relatively large movement of the tensioning roller 16 in the direction of the warp thread family 19 or away from it. This is achieved, for example, in the embodiment according to FIGS. 2 to 9, 12 to 14, 16 and 18 to 22 in that a row of support rollers 57 for the tensioning roller 16 is mounted in a stationary manner, while the other row of support rollers 58 is resiliently flexible in this way Holders is held that when these holders move, the distance between the row of support rollers 57 and the row of support rollers 58 also changes.

1 to 19, in which the support rollers 17, 18 or 57, 58 arranged in two rows are arranged at a greater axial distance, it is of course also possible to arrange the support rollers at a small axial distance from one another. In addition, instead of individual support rollers arranged axially one behind the other, a support roller can also be provided, which extends over the entire width of the warp thread array 19.

Deviating from the illustrated exemplary embodiments, in each of which the warp thread sheet 19 in the running direction second row of support rollers 18, 58 is arranged resiliently flexible, it can of course also be provided that the row of support rollers 17, 57, which are first in the running direction of the warp thread array 19, are arranged resiliently resilient. It is also possible to arrange the support rollers 17, 18 and 57, 58 of the two rows in a resilient manner, if appropriate also in common holders.

Combinations of individual features of the exemplary embodiments according to FIGS. 1 to 22 can be made without further notice. For example, in the embodiment according to FIGS. 20 and 21 or 22 it is possible to provide stationary support rollers which have a large diameter, for example corresponding to the support rollers 17 according to FIGS. 3 or 6. It is also possible to provide support rollers with a large diameter in the embodiments according to FIGS. 10 to 19 or support rollers with a small diameter in the embodiments according to FIGS.

The scope of protection of the invention is only determined by the patent claims. Otherwise, modifications can be made to the individual exemplary embodiments without thereby leaving the protected area.

Claims

claims

1. Device for tensioning a warp thread sheet (19) in a weaving machine with an over the width of the warp thread sheet

(19) extending tension roller (16) which is supported resiliently over its length, characterized in that the tension roller (16) is supported by means of a plurality of support rollers (17, 18; 57, 58) arranged over its length, which are supported in two rows parallel to the tensioning roller (16) are arranged, and that the support rollers (18, 58) are resiliently held in at least one row.

2. Apparatus according to claim 1, characterized in that the support rollers (18, 58) are held at least one row by means of holders which are resiliently pivotable in a resilient manner about axes parallel to the tensioning roller (16).

3. Apparatus according to claim 2, characterized in that the individual, resiliently arranged holder (20, 59, 62, 67, 71, 75, 76, 81, 88, 92) with one another by means of one or more stiffening elements (32, 60, 69 , 73, 74, 83, 87, 93) are connected.

4. Device according to one of claims 1 to 3, characterized ge indicates that the support rollers (17, 57) in the direction of the direction of the warp sheet (19) first row stationary and Support rollers (18, 58) of the second row in the running direction of the warp thread sheet (19) are arranged resiliently.

5. Device according to one of claims 1 to 4, characterized ge indicates that a common, resilient loading means (62, 82, 72, 95) is provided for several or all movable holders.

6. Device according to one of claims 1 to 5, characterized ge indicates that a parallel to the tension roller (16) verlauf¬ the support tree (7) is provided on which holder (8, 54, 90) for the stationary support rollers ( 17, 57) are arranged.

7. Device according to one of claims 1 to 6, characterized ge indicates that the pivotable holder (20, 59, 67, 71, 75, 76, 81) for the resiliently arranged support rollers on the holders of the stationary support rollers (17, 58) are attached.

8. Device according to one of claims 1 to 6, characterized ge indicates that the pivotable holder (20, 88, 92) for the resiliently arranged support rollers (18, 58) are arranged on the support tree (7).

9. Device according to one of claims 1 to 8, characterized ge indicates that on the pivotable holder or on the die¬ se stiffening elements spring-elastic loading means (21, 62, 70, 72, 82, 95) attack.

10. Device according to one of claims 1 to 9, characterized ge indicates that the pivotable holder (20, 82, 88) by means of spring-elastic loading means (21, 72, 82) on the support tree (7) or on the holders of stationary support rollers (17, 57) are attached.

11. Device according to one of claims 1 to 10, characterized in that means (27, 30, 66, 78) are provided for adjusting the loading force of the loading means.

12. Device according to one of claims 1 to 11, characterized in that leaf springs (21, 62, 72, 82) are provided as loading means.

13. The apparatus according to claim 12, characterized in that a substantially over the width of the warp yarn sheet (19) extending leaf spring (72, 82) is provided, which all holders (81, 88) of the resiliently resiliently arranged support rollers (58 ) charged.

14. The apparatus according to claim 13, characterized in that a substantially over the width of the warp yarn sheet (19) extending leaf spring (72, 82) is provided on which the holder (81, 88) of the resiliently arranged support rollers ( 58) are attached.

15. The device according to one of claims 1 to 11, characterized in that the pivotable holder (92) of the resiliently resiliently arranged support rollers (58) are attached to a common shaft (93) which runs parallel to the tensioning roller (16) and to which at least one load spring (95) acts.

16. The apparatus according to claim 15, characterized in that the shaft (93) is a hollow shaft, within which at least one torsion spring rod (95) is angeord¬ net as a loading spring.

17. The apparatus of claim 15 or 16, characterized gekenn¬ characterized in that the shaft (93) in or on the support tree (7) is mounted several times.

18. Device according to one of claims 1 to 17, characterized in that the stationary support rollers (17) are arranged such that they absorb a larger proportion of the forces F exerted by the warp thread assembly (19) on the tensioning roller (16) than the resilient flexibly arranged support rollers (18).

19. The apparatus according to claim 18, characterized in that the axes of rotation of the stationary support rollers (17) with respect to ei¬ ner bisector (31) between the feed direction of the warp thread sheet (19) to the tension roller (16) and the Abiauf¬ direction of the warp thread sheet (19th ) from the tensioning roller (16) are arranged at a smaller distance than the axes of rotation of the resiliently resiliently arranged support rollers (18).

20. The apparatus of claim 18 or 19, characterized gekenn¬ characterized in that the stationary support rollers (17) have a diameter which is approximately the same size as the diameter of the tensioning roller (16) or larger.

21. Device according to one of claims 1 to 20, characterized in that a deflecting element (9) for the Kettfa¬ denschar (19) is arranged in the running direction of the warp thread sheet (19) in front of the tension roller (16).

22. The apparatus according to claim 21, characterized in that the deflecting element is a deflecting roller (9) which extends over the width of the warp thread (19) and is supported by means of two rows of stationary support rollers.

23. The device according to claim 22, characterized in that the support rollers (10, 11) of the deflection roller (9) in the holders of the stationary support rollers (17, 57) of the tensioning roller (16) are arranged an¬.

24. The device according to one of claims 1 to 23, characterized in that one or more of the support tree (7) Sealing elements (97) are attached, which extend over the width of the warp thread sheet (19) and lie below the warp thread sheet (19) on the circumference of the tensioning roller (16).