DE102006061376A1 - Bowing tree for a loom - Google Patents

Abstract

The invention relates to a back rest (1) for a mechanical loom, wherein the warp thread movements in the warp direction are leveled out by a thread deflection element that is arranged on a mass-optimized spring leaf so as to be able to oscillate. For this purpose, a base (4) of the back rest is arranged in a mechanical loom frame (5), at least one spring leaf (6) is rigidly connected to the base (4) on a mounting side (7) and at least one thread deflection element (10) guiding the warp threads is arranged on an exterior (8) of the spring leaf opposite the mounting side (7). The mass of the spring leaf (6) in relation to a unit of length decreases towards the exterior (8) of the leaf spring (6).

Description

The The invention relates to a coating tree for a weaving machine, according to the preamble of claim 1.

One Such a petal consists of several parts, some of which rigid and others can be arranged movable and vibratory.

Already in the DE 3346030 A1 is described the problem of unfavorable dynamic behavior of such a bowing tree due to the large inertia of the oscillatory parts of the bowing tree. In addition to the continuous continuous movement of the warp threads through their incorporation into the fabric, the warp threads are stimulated by the shedding and the shot impact pulse to further movements and vibrations.

The vibratory String tree parts are affected by the movements and voltage fluctuations the warp threads in the warp direction to movements and oscillations causes. Are now the vibratory ones String tree parts due to their inertia unable to Movements of the warp threads without following a practically relevant phase shift, then the fluctuations of the warp tension are amplified and It creates a very high warp thread stress. This warp thread stress is particularly high when it comes to comparatively stiff warp thread material acting on the caused by said phase shift Difference between excitation (eg subject movement) and system response (Spreading tree movement) and the associated elongation of the warp material with a disproportionately large increase the warp tension responds.

Next quality losses in the goods by Kettfadenüberdehnungen and warp thread breaks the degree of utilization of the weaving machine also decreases due to downtimes, those by warp breaks or by stapling the warp threads be caused with each other at low warp tension.

To remedy these problems will be in the DE 3346030 A1 proposed a loom, the bowing of which has a contacted by the warp thread Fadenumlenkelement, which is supported vibrationally on at least one elastic member of the bowing tree.

To reduce the weight of the Fadenumlenkelementes and thus to further reduce the inertia of the moving parts of the bowing, is in the DE 3346030 A1 further proposed to distribute a plurality of elastic members uniformly over the measured perpendicular to the warp threads width of the Fadenumlenkelementes, because so the Fadenumlenkelement less rigid and thus can be built easier.

To execute the elastic member gives the DE 3346030 A1 different ways. For example, parts of elastomeric material may be used or parts of hard material whose shape provides the desired elasticity. Among other things, a leaf spring is proposed as an elastic organ.

Practice has now shown that the problems mentioned in the DE 3346030 A1 solutions mentioned can be resolved only in a limited speed range. At the high speeds of modern weaving machines of over 500 revolutions per minute, even the reduced by the measures mentioned moment of inertia of the oscillatory parts of the bowing tree is too high to follow the externally imposed motion profile. This is shown for. B. by the lifting of the warp threads from Fadenumlenkelement in certain phases of a Webzyklusses, especially when using very stiff warp thread material such as aramid or glass. As a result, the fluctuations in the warp thread tension curve and, in particular, the maximum values of the warp thread tension are intensified. This has the consequence that the disadvantages described above occur again.

Of the The invention is therefore based on the object, a bowing to create a weaving machine, even at high speeds of a Weaving machine ensures a durable, safe operation and a high quality of goods.

The solution This object is achieved according to the invention by the totality of specified in the claim 1 features.

At least a Fadenumlenkelement is over at least one leaf spring oscillates on a base body of the Attached to bowed tree. The leaf spring is rigid on a mounting side with the main body connected. On one of the attachment side opposite outside of Leaf spring is the Fadenumlenkelement arranged. So that the Fadenumlenkelement also very fast oscillations of the warp threads high speeds of the loom can follow is the leaf spring in the area of the outside massearm executed d. H. on a unit of length referred mass of the leaf spring increases from the mounting side outside down.

It must bezo on a unit of length bezo gene mass not continuously decrease in the direction of the outside, but can also gradually and / or only in sections of the total length of the leaf spring decrease.

By the embodiment of the invention Leaf spring is the inertia for the translational part of the movement and the mass moment of inertia for the rotatory portion of the movement is reduced to an optimal value. As a result, the desired high natural frequency of the oscillatory parts reached the bow tree.

On the faster moving outside the leaf spring is a reduction in mass particularly advantageous because there against the inertia and the mass moment of inertia acting accelerations are particularly high.

Thereby elevated the ability the Fadenumlenkelements the warp thread movements without a practical to follow relevant phase shift. The warp tension profile can by such an embodiment can be favorably influenced by reducing voltage spikes and voltage dips be avoided, especially at high weaving machine speeds.

A Leaf spring in the context of this invention is not necessarily in one piece educated. In particular, multipart layered leaf springs are here also subsumed under the term leaf spring.

According to one preferred embodiment the invention is the leaf spring at substantially the same thickness towards the outside running with decreasing width. Easy-to-manufacture leaf springs have, for example, a triangular or a trapezoidal shape. Depending on the desired spring characteristic can the width of the leaf spring towards the outside but also according to a certain decrease mathematical function. Furthermore, a leaf spring possible, in the direction of the outside both the width and the thickness decreases or a leaf spring, in which only the thickness decreases.

One Advantage of these designs the leaf spring becomes in consideration of the stress distribution recognizable in the leaf spring. Due to the rigid attachment of the leaf spring on the body results in the region of this attachment side, the highest bending moment bending the leaf spring as it moves through the warp thread movements happens. By narrowing towards the outside or thinning Leaf spring is now the highest Bending moment in the widest or thickest area of the leaf spring, namely added to the attachment side. The to the leaf spring outside decreasing bending moment is narrowed by a corresponding or thinner Leaf spring section added. This is the stress distribution more even than in the leaf spring For example, it would be a rectangular leaf spring. On this is in relation to the strength requirement on the leaf spring Optimal material utilization with reduced mass moment of inertia reached.

There the functions suspension and thread guide are separate and respectively associated with a component, namely the suspension of the leaf spring and the thread guide the Fadenumlenkelement, Each component can be optimized with regard to its assigned function become. The Fadenumlenkelement z. B. optimized in terms of surface quality, because the Fadenumlenkelement is directly in contact with the warp threads and therefore the Oberfächenqualität the Fadenumlenkelementes a significant importance in terms of the quality of the product due.

at An article change, a Fadenumlenkelement advantageous simply and quickly replaced with another Fadenumlenkelement its surface properties adapted to the new article. A simpler and faster Article change can be achieved by simply releasing the deflection element on the leaf spring in the sense of a quick-change connection on supports become. For this purpose, at least one leaf spring on its outside For example, be provided with a groove in which the deflection with a matching counterpart simply inserted and tightened or clamped. The effort regarding the surface quality of the leaf spring In contrast, in favor of a simple and cheap production of the leaf spring be kept low because the leaf spring does not come into contact with the warp threads.

Further Aspects of the invention result from the use of several Leaf springs, which spread over perpendicular to the warp threads extending width of the Fadenumlenkelementes are arranged. In case of changes The width of the fabric can simply be a corresponding number of leaf springs taken away in the edge area or additionally mounted to so the string tree to the changed Adjust the width of goods. It can the same spring characteristics of the bow tree with little effort over different Widths of goods to be maintained.

If the leaf springs are now designed according to a further preferred embodiment with different spring stiffnesses, this results in further effects of the invention. When using a stiff Fadenumlenkelementes and the combined use of multiple leaf springs with different spring stiffness on the Warp warp effective total spring stiffness of the leaf springs are selectively influenced and set to specific values.

there Can by clever combination and arrangement of a small selection on leaf springs with different spring stiffness a large number be set to total spring stiffnesses.

by virtue of the said assignment of functions suspension and thread guide to the components leaf spring and Fadenumlenkelement it is also possible, both Components in terms of their respective function and one possible optimally low mass.

Becomes For example, the Fadenumlenkelement, through the use of several Leaf springs, over the width of the warp threads supported in several places, so the Fadenumlenkelement with lower strength and thus also executed with lesser mass be, as in one execution in which the Fadenumlenkelement is mounted only at the ends.

The Fadenumlenkelement can for example made of lightweight plastic, made of fiber-reinforced plastics or other composites. The mass of the oscillatory parts of the String tree is thus further reduced and the natural frequency of Facility increased.

According to one another preferred embodiment in connection with the use of multiple leaf springs have the Leaf springs in the edge region of the Fadenumlenkelements another spring stiffness on as the leaf springs in the central region of the Fadenumlenkelementes.

On this way you can undesirable Kettfadenlängenveränderungen and thereby caused deviations of the warp tension in the edge region completely balanced or at least minimized. It can be advantageous a multi-part or flexible Fadenumlenkelement provided.

As well is it with this version possible different Warp tension of the edge warp and thereby advantageous To achieve web conditions in the edge region of the fabric. A different one Incorporation of the warp threads in the edge area compared to the warp threads in the background fabric can be a such action require. This can, for example, in tissues with insertion edges of Be the case, which have different types of weaves in the base fabric than in the area of the insertion edges, resulting in another edge area optimal warp tension results than in the remaining area of the Tissue.

One Another aspect of the invention is the superposition of a second movement over the spring movement the leaf spring. The superimposed second movement leads preferably the entire base body with the attached elements through. This is the main body of the Bowed tree movably arranged on the loom and preferred by a drive operable. The drive can do this from the main drive of the weaving machine via geared Means be derived or it is a separate, controlled drive for the activity the body movement provided on the bow tree.

Of the body can be both translational, as well as rotational movements To run. As separate drives are electrical, hydraulic or pneumatic Actuators possible.

at a preferred embodiment of the invention the main body for example, by means of an electric drive about a horizontal, vertical to the warp direction lying axis rotatable, so that the leaf spring pivoted about an axis located near its attachment side becomes. The warp tension over the different phases Each web cycle can be actively influenced in this way.

A another possibility one of the leaf spring movement superimposed to achieve second movement is the fasteners movable on the attachment side of the leaf spring, z. B. pivotable on the body to arrange so that not the entire body is moved.

Movable powered stringers are under the term "active String Tree Systems "already are known and are usually also to compensate for warp tension fluctuations used.

Regular, in each web cycle recurring voltage fluctuations as for example caused by the shedding, can with the active Streichbaumsystem as far as possible be compensated. The leaf spring according to the invention compensates beyond occurring length shifts and stress peaks of the warp threads, which occur so briefly that the drive of the active bowing tree can not respond in time, for. On voltage spikes, which are caused by the leaf stop. Furthermore, will be unpredictable deviations from the expected Voltage curve balanced.

In the terry weaving can be with such superimposed movements of the bow tree voltage fluctuations in the pole or the basic chain by actively initiated stroking tree movements At the same time unpredictable voltage deviations and extremely fast voltage spikes are compensated by the leaf spring. In addition, the pole or base voltage during the weaving of smooth areas such. As borders are actively increased and lowered in terry cloth again to obtain a uniform Polbildung terry.

Also the voltage curve in the basic chain of a terry machine and in other loom types be positive with such a design influence. For example, the basic chain can be used for terry toweling for the Period of each full stop briefly with a higher voltage operated to obtain an improved appearance.

A Particularly advantageous application is the execution with a superimposed Movement at every stop of the loom. Especially during prolonged shutdowns of Loom, it is advantageous to lower the tension in the warp threads, about negative effects the warp threads too avoid. Such impairments often lead to so-called focal points in the tissue and thus to significant quality losses.

Around To avoid this is the body at each machine stop as far as in the appropriate direction pivoted or shifted, that the warp tension is below a predetermined value sinks.

To the Restart of the loom, the discharge is reversed again, by the basic body so far moved or pivoted in the opposite direction until the warp tension required in the current weaving operation is reached. This can be almost instantaneous or over a period of time done according to a ramp function. In the latter case will the warp tension is increased continuously or gradually until the desired one Value is reached.

A different possibility the warp tension adjustment at the restart of the loom is a short-term spanning the warp threads z. During of the first reed stop. This is the warp tension before the first reed stop to a value above the warp tension value for the ongoing web operation increased and then lowered according to a predetermined course.

The Selection of the suitable starting method on restart depends on Warp thread material, binding and other factors. The necessary control devices for relaxing and re-tensioning the warp threads with suitable tension measuring elements are well known and therefore will not be described here.

A further preferred embodiment The invention comprises at least one mechanical stop for Limitation of the movement of the Fadenumlenkelementes. This can be fixed be arranged on the loom or made adjustable. With the help of the stop let yourself make a stiff string tree from the sprung string tree or the Spring travel of the leaf spring is limited to a predetermined value. The effect of the stroke leaves either manually on and off or by a corresponding Drive. A controlled drive for putting the stop into operation allows for example, a weaving operation that in certain phases with rigid Spreading tree and in other phases with sprung string tree expires.

Of the Stroke can be caused by the above-described superposition of a second movement via the spring movement the leaf spring are approached. For this, the movable at the Loom arranged basic body the bowing tree with the attached leaf spring in the direction of the rigidly attached to the weaving machine stop driven to the Stop on the leaf spring is effective.

According to one another preferred embodiment is a second stop on the first stop opposite Side of the leaf spring provided. With a stop on each side the leaf spring can be the path of the leaf spring both when loading be limited as well as relieving the leaf spring. When loading the leaf spring serves to stop an overload of the leaf spring to avoid. To release the tension in the warp threads, z. B. machine downtime, for example Chain drained from the warp beam. The leaf spring is relaxed and moves until it stops at the corresponding stop. As soon as the leaf spring is resting on the stop when relaxing and another chain is drained, the tension in the warp almost goes abruptly against zero. In this way, the warp tension can be strong be lowered without leaving the chain on the warp beam to a great length.

Of the last described relaxation process can also be carried out instead of the chain the goods are drained from the goods tree or by both chain and goods is drained to the leaf spring is at the stop.

The Fadenumlenkelement is preferably designed as a continuous bar and rigidly attached to the leaf spring. It can, however, according to one whose preferred embodiment of the invention is also movably attached to the leaf spring and formed in a different shape. If, for example, a deflecting roller is used as deflecting element, then the warp threads no longer slide over the surface of the thread deflecting element, but roll over it. Additional warp tension caused by sliding friction between warp threads and deflecting can be avoided with such an embodiment.

On the leaf spring effective damping means indicate another preferred embodiment of the present invention. Already the use of a layered leaf spring brings certain damping behavior with himself. additionally can to Setting a specific damping one or more friction lamellae between the individual layers be used.

The The invention further comprises a loom with the described Stringing tree, as well as a leaf spring for use in such Back rest.

The The invention and other advantages that follow are set forth below based on an embodiment even closer explained.

In the figures shows

1 a perspective view of a coating tree according to the invention with its arrangement in the weaving machine frame,

2 the side view of a weaving machine according to the invention with bowing,

3 an enlarged illustration of the bow tree from the 2 and

4 a diagram with the comparison of the warp tension profile in a conventional and a spreadsheet according to the invention.

In the 1 . 2 and 3 the arrangement and structure of a bowing tree according to the invention is shown.

The warp threads 9 run from the warp beam 2 over the bowing tree 1 to the Fachbildemitteln 3 and continue until they are finally wound up as tissue on the fabric tree, not shown.

In this embodiment, the main body 4 of the bow tree 1 over the main body carriers 15 . 15 ' with the weaving machine frame 5 . 5 ' connected. Here is the bow tree 1 with the main body 4 via linear guides 11 . 11 ' in the vertical direction and via linear guides 13 . 13 ' displaceable in horizontal direction. During the web operation is the bow tree 1 however, fixed in position by the locking screws 12 . 12 ' . 14 . 14 ' the linear guides are screwed tight.

In the horizontal linear guides 13 . 13 ' are the pillow block bearings 16 . 16 ' arranged displaceable and lockable. In the pillow cases 16 . 16 ' is the main body 4 rigidly stored. In the illustrated embodiment, the main body 4 tubular, but it may also have any other, any cross-section.

Several, arranged over the weaving width arranged headband 17 fix the holding plates 18 by nuts 19 with lock washers 20 on the body 4 ,

On the holding plates 18 are the leaf spring carrier 21 by means of screws 22 attached. A terminal block 25 is rigid with the leaf spring carrier 21 connected, z. B. screwed.

In the area of the free end of the leaf spring carrier 21 is a baffle 23 through the screw 24 rigidly connected to the leaf spring carrier. The baffle 23 serves to deflect the warp threads 9 and is provided with an appropriate surface treatment, which may vary depending on the used warp material, in order to avoid a deterioration of the product quality by the contact of the warp slides over the baffle.

The leaf spring 6 is with its attachment side 7 between the clamping surface 27 of the terminal block 25 and the pressure piece 26 firmly clamped. This is the pressure piece 26 by means of clamping screw 28 tightened.

Thus, the attachment side 7 the leaf spring 6 rigid with the main body 4 connected.

At the free end of the leaf spring 6 , the outside 8th is the deflection element 10 by means of the fixing screw 29 and fixing nut 30 rigid with the leaf spring 6 connected.

In the area of the outside 8th the leaf spring 6 is at a certain distance in the clamping direction, ie in the direction in which the leaf spring 6 when increasing the tension in the warp threads 9 Bends, a mechanical stop 31 arranged in the form of a stop screw. This stop is fixed in the desired position by the lock nut 32 ,

The feature of the invention to the outside 8th decreasing mass of the leaf spring 6 per unit length is in this Ausführungsbei achieved by the triangular shape of the leaf springs. In the area of the relatively fast moving outside 8th the leaf springs 6 There is such a small mass that is due to the movement of the warp threads 9 generated accelerations a relatively low inertia opposes. As a result, the entire oscillatory system of the coating tree reacts highly dynamically and keeps the tensile stresses in the warp threads in a low range over the entire weaving cycle.

The function of the coating tree according to the invention is in 3 visible, noticeable. When tying the warp threads 9 a force generated by the warp tension acts on the deflecting element 10 and bends the leaf spring 6 in the direction of the stop 31 , In web mode is the leaf spring 6 between the first position of the leaf spring shown in solid lines and the second position shown in dashed lines, in which the outside 8th the leaf spring near the stop 31 located. In the first illustrated position is the leaf spring 6 completely relaxed, ie unloaded and in the second position shown is the leaf spring 6 almost maximum tension. The stop 31 is set to overload the leaf spring 6 is excluded. The mechanical stop 31 In other embodiments, it can also be designed to be adjustable during operation and positioned at different positions in different operating phases, so that the maximum leaf spring travel is limited or expanded.

During ongoing weaving operation, the leaf spring moves 6 usually not over the entire range from the first, completely relaxed position to the maximum cocked position at the stop 31 but in a limited area somewhere between these two extremes. The width of this area, ie the amplitude of the leaf spring oscillations in the current weaving operation depends on various factors, eg. Example of the spring characteristic of the leaf spring, the material of the warp threads, and the size of the Fachhubes.

At a standstill of the loom, the warp tension is lowered by either chain drained from the warp beam or goods from the fabric tree is drained. This relaxes the leaf spring 6 and the deflecting element 10 moves toward the first, unloaded position until a desired low warp tension is achieved.

If the warp thread displacement is to be limited during this relaxation process, this can be achieved by a second stop, which is not shown here. The second stop will be on the first stop 31 opposite side of the leaf spring 6 arranged and adjusted so that the leaf spring 6 while relaxing the warp threads 9 already runs after a slight way in the direction of the first, unloaded position on the second stop. Even a slightest further deflation of the warp or goods from the warp or cloth tree then causes a drop in the warp tension to zero.

An embodiment according to claim 8, which allows a second, the leaf spring movement superimposed movement is not shown. Starting from the in the 1 illustrated embodiment, however, such an embodiment can be easily achieved by the tubular body 4 Rotationally movable in the pedestal bearings 16 is stored. A controlled rotary drive is rigidly mounted on the pillow block and the drive shaft of the rotary drive is connected to the rotatably mounted body 4 operatively connected. The corresponding control signals receives the rotary drive preferably from the loom control via suitable signal lines.

Another way to generate the second superimposed motion is the terminal block 25 rotationally movable or translationally displaceable on the leaf spring carrier 21 to store and drive with a controlled drive.

In the diagram in 4 on the abscissa, the loom rotation angle is shown in degrees [°] for approximately two cycles and the ordinate indicates the corresponding warp tension in centi-newton [cN]. The characteristics were both recorded at a loom speed of 600 rpm.

A first, continuous characteristic 33 shows the course of the tension in the warp threads during operation of a loom with a coating tree according to the invention.

A second dashed curve 34 shows the typical course of the tension in the warp threads in a conventional coating system, without mass-optimized coating tree. Due to the higher inertia of the oscillatory parts in the conventional system, the system can no longer follow the fast movements of the warp threads at high speeds of the weaving machine and lift the warp threads in certain phases of the Webzyklusses from the deflection, shortly thereafter to rebound again on the spring-loaded deflection. The fast movements of the warp threads are caused for example by the rapid movements of the shedding means at correspondingly high speeds of the weaving machine. This causes the high maximum values of the warp tension, which are clearly visible in the course of the characteristic curve.

Especially the steep declines and Increases in the warp tension in the curves form the described Operation with a lifting of the warp threads from the deflection and the subsequent impact on the deflector. These high changes mean the warp tension within a short period of time a high load on the warp threads and thus a source of error for the entire web process.

When comparing the two characteristics 33 and 34 it becomes clear that the course of the warp tension 33 is advantageously compensated with a highly dynamic, spreadsheet according to the invention. Ie. the maximum values of the warp thread tension are clearly lower and the minimum values of the warp thread tension are clearly higher. The occurring warp tension values can therefore be restricted to a very narrow range.

This allows optimal adjustment of the warp tension for each Items. The load and impairment of the warp threads is significantly lower, whereby the process reliability in Webbetrieb and the goods quality climb.

1

back rest

2

warp beam

3

Shedding means

4

body

5

Webmaschinengestell

5 '

Webmaschinengestell

6

leaf spring

7

mounting side

8th

outside

9

warp

10

deflecting

11

linear guide

11 '

linear guide

12

locking screws

12 '

locking screws

13

linear guide

13 '

linear guide

14

locking screws

14 '

locking screws

15

Base carrier

15 '

Base carrier

16

Plummer

16 '

Plummer

17

headband

18

holding plates

19

mother

20

lock washer

21

Leaf-spring support

22

screw

23

baffle

24

screw

25

terminal block

26

Pressure piece

27

clamping surface

28

clamping screw

29

fixing screw

30

fixing nut

31

attack

32

locknut

33

curve

34

curve

Claims (18)

Bowing tree ( 1 ) for a weaving machine which, in the course of the warp thread, follows the warp beam ( 2 ) of the weaving machine, wherein a main body ( 4 ) of the coating tree in a weaving machine frame ( 5 ), wherein at least one leaf spring ( 6 ) on a fastening side ( 7 ) rigidly with the main body ( 4 ), and wherein on one of the attachment side ( 7 ) opposite outside ( 8th ) of the leaf spring at least one of the warp threads ( 9 ) leading thread deflection element ( 10 ), characterized in that the mass of the leaf spring related to a unit of length ( 6 ) towards the outside ( 8th ) of the leaf spring ( 6 ) is decreasing. A spreadsheet according to claim 1, wherein the width and / or the thickness of the at least one leaf spring ( 6 ) towards the outside ( 8th ) of the leaf spring is decreasing. Stripe according to claim 2, wherein the at least one leaf spring ( 6 ) has a triangular or trapezoidal shape at substantially uniform thickness. Stripe according to one of claims 1 to 3, wherein a plurality of leaf springs ( 6 ) distributed over the width of the warp threads ( 9 ) are arranged. Stripe according to claim 4, in which the leaf springs ( 6 ) have different spring stiffnesses. Stripe according to claim 5, in which the leaf springs ( 6 ) in the edge region of the Fadenumlenkelements ( 10 ) have a different spring stiffness than the leaf springs in the middle. Stripe according to one of claims 1 to 6, wherein the Fadenumlenkelement ( 10 ) consists of several individual parts distributed over the width of the warp threads ( 9 ) are arranged side by side. Stripe according to one of the preceding claims, wherein the spring movement of the leaf spring ( 6 ) a second movement can be superimposed. Stripe according to claim 8, wherein the base body ( 4 ) is movably arranged on the loom, so that the second movement by a movement of the base body ( 4 ) is executable. A spreadsheet according to claim 8 or 9, wherein the Drive for controlled actuation the second movement derived from the main drive of the loom is. Stripe according to claim 8 or 9, with a separate electric, hydraulic or pneumatic drive for controlled Actuation of second movement. Stripe according to one of the preceding claims, with at least one mechanical stop ( 31 ) for limiting the movement of the leaf spring ( 6 ). A bow tree according to claim 12, wherein at least one mechanical stop ( 31 ) is designed adjustable. Stripe according to one of the preceding claims, with a movable on the leaf spring ( 6 ) attached deflecting element ( 10 ). Stripe according to claim 14, wherein the deflecting element ( 10 ) is designed as a deflection roller. Stripe according to one of the preceding claims, with on the leaf spring ( 10 ) effective damping agents. Weaving machine, characterized by a bowing tree according to one the aforementioned claims. A leaf spring for a coating tree according to one of claims 1 to 16, with a fastening side ( 7 ) and one of the attachment side ( 7 ) opposite outside ( 8th ) of the leaf spring, characterized in that the relative to a unit length mass of the leaf spring ( 6 ) towards the outside ( 8th ) of the leaf spring ( 6 ) is decreasing.