EP1867769A1 - Pattern beam device - Google Patents

Abstract

The pattern-rendering warp beam arrangement (1) for a knitting machine, comprises a pattern-rendering warp beam (2), which is rotatably mounted in a frame and on which a pattern-rendering yarn is wound that is led through a yarn drawing mechanism. The pattern-rendering warp beam has a regulatable brake mechanism and a slip drive mechanism. The slip drive mechanism consists of an actuated element (7), which acts with a friction grip upon the pattern-rendering warp beam. The actuated element acts upon the circumference of the cylindrical pattern-rendering warp beam. The pattern-rendering warp beam arrangement (1) for a knitting machine, comprises a pattern-rendering warp beam (2), which is rotatably mounted in a frame and on which a pattern-rendering yarn is wound that is led through a yarn drawing mechanism. The pattern-rendering warp beam has a regulatable brake mechanism and a slip drive mechanism. The slip drive mechanism consists of an actuated element (7), which acts with a friction grip upon the pattern-rendering warp beam. The actuated element acts upon the circumference of the cylindrical pattern-rendering warp beam. The actuated element is designed as a brush belt and causes a complete revolution. The actuated element acts upon several pattern-rendering warp beams. Several pattern-rendering warp beams are laid out at a single plane and the actuated element is led more or less in a rectilinear manner above the pattern-rendering warp beams aligned at the plane. The pattern-rendering warp beams are aligned at several planes. An actuated element is incorporated at every plane and the actuated elements have a common drive mechanism (28). The actuated element drives the pattern-rendering warp beams in several planes. The yarn drawing mechanism has a yarn accumulating/delivery unit for the additional maintenance of yarn tension. The yarn accumulating/delivery unit has switching components for actuating the brake mechanism. The switching components consist of a first sensor that indicates an accumulated state of the yarn accumulating/delivery unit and a second sensor that indicates a depleted condition of the yarn accumulating/delivery unit. The first sensor enables an activation of the brake mechanism and the second sensor disables the activation of the brake mechanism. The sensors are designed as non-contact sensors. The yarn accumulating/delivery unit consists of a weight-loaded and vertically-movable yarn guidance mechanism.

Description

The invention relates to a pattern tree arrangement for a knitting machine with at least one pattern tree, which is rotatably mounted in a frame and on which at least one pattern thread is wound, which is guided by a thread take-off arrangement.

To produce a patterned knitted fabric pattern threads are subtracted from so-called pattern trees and fed to the knitting machine. Several pattern trees are stored in a frame, with each pattern tree usually provides a pattern laying with threads. On a pattern tree, which usually extends at least over the working width of the knitting machine, several threads are wound or sharpened with the same voltage and length in juxtaposed sections. The number of winding sections is dependent on the number of side rapids, which are divided over the working width of the knitted fabric. The threads are Depending on the course of the pattern, they are integrated into a product base and thus create a pattern in the knitted fabric. Depending on the pattern, the thread consumption of a thread drawn from a pattern tree is very different, which also causes different peripheral speeds of the pattern tree. This peripheral speed can vary constantly. The peripheral speeds of different pattern trees in the pattern tree arrangement may also be greatly different.

In general, the pattern tree is provided at its two outer shaft ends with roller bearings and stored on bearings. On one of the two shaft ends is a brake disc. With the aid of a brake band and brake weights, the pattern tree is braked. On the one hand, this is necessary in order to generate a thread tension necessary for the knitting process. On the other hand, an uncontrolled twisting of the pattern tree is avoided. The adjustment of the brake is relatively complicated. On the one hand, the brake must not brake too hard in order to avoid an excessive increase in the thread tension when accelerating the pattern tree. On the other hand, the brake must nevertheless apply a certain braking effect so that the pattern tree does not uncontrollably rotate when the thread take-off is ended or reduced. In this case, the thread tension would decrease greatly.

The disadvantage of the known type to supply pattern threads, especially at high operating speeds of the knitting machine. At high machine speeds results in a high yarn consumption and thus an increased peripheral speed of the pattern trees. When a Pattern requires a very different thread consumption, the thus changing peripheral speeds of the pattern trees adversely affect the thread tension of the pattern threads. The mass of the pattern trees must be accelerated or decelerated accordingly.

The invention has for its object to keep the thread tension on a pattern tree even with a high-speed knitting machine within predetermined limits.

This object is achieved in a pattern tree arrangement of the type mentioned above in that the pattern tree has a slip drive.

In a slip drive, a driving element, which may for example be driven by a motor, communicates with the pattern tree in such a way that a relative movement between the pattern tree and the driving element is possible. However, the driving element continuously applies a driving force to the pattern tree which sets it in rotation when no other forces act on the pattern tree. With this configuration, it is now possible to ensure that the forces necessary for accelerating the pattern tree are not only applied by the pattern threads. Ideally, the slip drive drives the pattern tree even so that without other external forces, the scope of the pattern tree has the speed that must be achieved with the largest thread consumption. Accordingly, inadmissibly high tensions in the withdrawn yarns are avoided because the pattern tree, when driven by the slip drive, keeps the yarns continuous nachliefert without the threads themselves must apply an excessively large train. On the other hand, of course you can slow down the pattern tree, as before. If one tunes the braking forces and the driving forces well, then the stresses acting on the threads are kept small. A slip drive can work both contactless, for example by means of a magnetic coupling, as well as by a frictional engagement.

Accordingly, in a preferred embodiment, the slip drive on a moving element which acts with a frictional engagement on the pattern tree. As long as the moving element moves, the pattern tree is rotated by the frictional engagement. However, if braking forces act on the pattern tree, then the pattern tree rotates more slowly than the moving element is moved, so that there is a relative movement between the pattern tree and the moving element.

Preferably, the moving element acts on the circumference of the pattern tree. This is a sufficient lever arm available with which the moving element can transmit torque to the pattern tree. The drive through the moving element is well utilized.

Preferably, the moving element forms a circulation. A circulation, for example, a circumferential loop, can rotate permanently, so that it can be driven in turn by a rotary drive, for example.

In a particularly preferred embodiment, the moving element is designed as a brush belt. In this case, the brush belt is preferably positioned so that the circumference of the pattern tree or connected to the pattern tree drive pulley presses with its circumference with a portion each in the bristles. In this case, the bristles sweep along the surface of the pattern tree circumference and rotate it forward. By changing the speed of the drive of the brush belt, the rotary thrust can be changed.

Preferably, a plurality of pattern trees are provided and the moving element acts on a plurality of pattern trees. Since the slip drive only specifies a maximum drive speed for the pattern trees, but otherwise the pattern trees can be individually controlled in their peripheral speed, one can drive several pattern trees with a single moving element. This allows a relatively simple constructed pattern tree arrangement with comparatively few drives.

It is preferred that a plurality of pattern trees are arranged in a plane and the moving element is guided substantially rectilinearly over the pattern trees arranged in the plane. For example, the pattern trees may all be guided along a run of the movable member so that the moving member drives all of the pattern trees in that plane.

Also pattern trees can be arranged in several, in particular parallel planes, wherein in each plane a moving element is arranged and the moving elements have a common drive. This can for example be realized so that each moving element has its own drive wheel and all drive wheels are driven together by a drive.

In an alternative embodiment it can be provided that pattern trees are arranged in several, in particular parallel planes, the moving element drives pattern trees in several levels. If the moving element is guided as a loop, then this loop is passed through several levels.

The pattern tree preferably has a controllable braking device. Thus, the control of the peripheral speed of the pattern tree in two directions is possible. First, the pattern tree can be driven by the slip drive, so be brought to a higher speed when a high thread consumption is present. On the other hand, the pattern tree can also be selectively braked by the controllable braking device when the thread consumption is lower. By the slip drive and the braking device, the peripheral speed of the pattern tree can be very specifically adapted to the thread consumption.

The thread withdrawal arrangement preferably has a thread store. Since the model tree also has a certain inertia with slip drive and braking device, the thread store is able to absorb or release short-term required amounts of additional thread, so that the thread train or the thread tension can be made uniform at the site of action.

The thread store preferably has switching means for actuating the braking device. The slip drive acts permanently on the pattern tree and drives it. Accordingly, a control of the slip drive is not required. The braking device, however, can act much faster on the pattern tree, so that it is advantageous to use the thread storage as a criterion for whether the pattern tree should be braked or not.

In a practical embodiment, it is provided that the switching means comprise a first sensor, which indicates a filled state of the thread store, and a second sensor, which indicates a deflated state of the thread store, wherein the first sensor triggers an activation of the braking device and the second sensor the activation of the braking device terminated. In any case, if the thread store is filled, no subsequent delivery of the thread from the pattern tree is required in the short term. Accordingly, the braking device can decelerate or even stop the pattern tree. If, however, the thread store is emptied, then the slip drive should be able to drive the pattern tree readily, so that the braking device is released. Conveniently, you will not order the two sensors not only in the absolute end positions of the thread store, but just before so that, for example, the slip drive has a certain amount of time available to bring the pattern tree to a certain speed, on the other hand, the braking device has a certain amount of time to decelerate the pattern tree.

Preferably, the sensors are designed as non-contact sensors. This keeps the wear and the susceptibility to errors low.

Preferably, the thread store on a weight-loaded and vertically movable thread guide. The weight then pulls the thread guide down in the direction of gravity. A string pulls the thread guide upwards against the weight if the pattern tree does not supply an adequate amount of thread. This is a relatively simple embodiment to load the thread store or to empty it.

Fig. 1

eine schematische Seitenansicht einer Musterbaumanordnung,

Fig. 2

einen Musterbaum mit Schlupfantrieb und Bremsen in vergrößerter perspektivischer Darstellung,

Fig. 3

eine schematische Darstellung zur Erläuterung des Antriebs und

Fig. 4

eine vergrößerte Darstellung eines Fadenspeichers.

The invention will be described below with reference to a preferred embodiment in conjunction with the drawings. Herein show:

Fig. 1

a schematic side view of a pattern tree arrangement,

Fig. 2

a pattern tree with slip drive and brakes in an enlarged perspective view,

Fig. 3

a schematic representation for explaining the drive and

Fig. 4

an enlarged view of a thread storage.

1 shows a pattern tree arrangement 1 with a plurality of pattern trees 2, each of which carries a plurality of thread windings 3. The number of filament winding 3 on Each pattern tree 2 corresponds to the number of repeats in a knitted fabric, which is produced on a knitting machine, not shown, in particular a warp knitting machine. The number of pattern trees 2, however, corresponds to the number of pattern bars used. The pattern threads of a pattern tree are usually supplied to a separate, not shown pattern laying bar in the knitting machine.

Based on Fig. 2, a single pattern tree 2 will now be explained in more detail. The remaining pattern trees 2 are stored according to the pattern tree arrangement 1 and controlled with respect to their rotational or peripheral speed.

Each pattern tree 2 is rotatably supported at its axial ends via roller bearings 4, which are fixed in a frame, not shown.

In the region of an axial end of the pattern tree 2, a slip drive 5 is arranged, which in the present embodiment has a guided as a circumferential loop 6 brush belt 7, which acts on a peripheral portion 8 of the pattern tree 2. The pattern tree 2 and the brush belt 7 are positioned to each other so that the circumference of the pattern tree 2 is slightly immersed in the bristles 9 of the brush belt 7. When the brush belt 7 is moved in the direction of an arrow 10, then rub the bristles 9 over the peripheral portion 8 of the pattern tree 2, thereby driving the pattern tree 2 in the direction of the arrow 10 directed parallel to the arrow 11 at.

The pattern tree 2 is thus driven by friction of the brush belt 7. When the pattern tree 2 is braked by other forces, then slide the bristles 9 of the brush belt 7 over the peripheral portion 8 of the pattern tree 2, without that the pattern tree 2 rotates at a peripheral speed of the brush belt 7 corresponding peripheral speed. The pattern tree 2 can rotate slower or even stand still.

The slip drive 5 is thus responsible for the rotational drive of the pattern tree. 2

To brake the pattern tree 2, a braking device 12 is provided, which can be activated to decelerate the pattern tree 2, or can be deactivated to allow a drive through the brush belt 7.

The braking device 12 has a brake shoe 13, which may be formed in the present embodiment as a rubber stopper. The brake shoe 13 is pressed by an actuator 14 against the circumference of the pattern tree 2 or removed from the periphery. The actuator 14 may be formed, for example, as a pneumatic cylinder, as a hydraulic cylinder or as an electromagnetic actuator. In any case, the actuator 14 may be very simple, because he basically just two positions, namely activated brake or deactivated brake must take.

As can be seen from Fig. 2, a pattern thread 15 is withdrawn from each roll 3. The pattern thread 15 is passed through a yarn store 16, which will be explained in more detail in connection with FIG.

The yarn store 16 has an inlet-side rod 17 and an outlet-side rod 18, over which the pattern thread 15 is guided. Between the two rods 17, 18 of the thread is loaded by a weight 19 which is suspended on an eyelet 20, through which the pattern thread 15 is guided. The weight 19 pulls the pattern thread 15 between the two rods 17, 18 in the direction of gravity down. The yarn store 16 thus has a capacity which corresponds approximately to twice the travel path of the weight 19. In a manner not shown, the weight is guided vertically, so that the pattern thread 15 is always guided vertically.

The weight 19 simultaneously acts as a transmitter for a first sensor 21 and a second sensor 22. The first sensor 21 is arranged in the vicinity of the lower end of the yarn store 16. Thus, if the weight 19 comes close to the first sensor 21, then this is an indication that the thread store 16 is filled and further replenishment of the pattern thread 15 is not required. When the weight 19 comes close to the first sensor 21, then the first sensor 21 (or an associated, not shown control) triggers the braking device 12, so that the pattern tree 2 is stopped or its rotational speed is reduced. When the pattern thread 15 is further pulled off, the weight 19 is pulled upwards and then comes close to the second sensor 22. When the weight 19 comes close to the second sensor 22, this is an indication that the thread store 16 is practically emptied. In this case, the pattern thread 15 must be redelivered again from the winding 3. In this case, the braking device 12 is deactivated and the slip drive 5 drives the pattern tree 2 until the weight 19 is in the range of the first sensor 21.

The two sensors 21, 22 are designed as non-contact sensors, for example as magnetic sensors.

As can be seen from FIG. 1, the pattern trees 2 are arranged in different planes, in the present exemplary embodiment in six planes, wherein each plane in turn accommodates six pattern trees 2. The pattern trees 2 a plane are driven by a common brush belt 7.

Each brush belt 7 passes over two pulleys 23, 24. It also takes place between the pulleys 23, 24 on the one hand and the brush belt 7 on the other hand, a frictional engagement. It is also possible to provide the brush belt 7 on its inside with a tooth profile, so that at least between the guide roller 23 and the brush belt 7, a mold engagement can be made.

A drive belt 26 is guided over drive wheels 25 and guided between pulleys of adjacent planes via tension rollers 27. The drive belt 26 is driven by a drive motor 28. All brush belts 7 are thus driven by the same drive 28, so that one can easily ensure that all brush belts 7 have the same peripheral speeds.

In a modification, not shown, you can also lead a brush belt 7 through all levels so that it acts on all the pattern trees 2. Again, this is one way to easily ensure that all the pattern trees 2 can be driven at the same peripheral speed.

Each pattern tree 2 thus has an individually controllable brake and a common with other pattern trees 2 slip drive. The slip drive 5 is designed so that it can drive each pattern tree 2 with the maximum required take-off speed of the pattern threads 15. This prevents that at maximum thread consumption unduly high voltages in the pattern threads 15 arise. By decelerating a pattern tree by means of the braking device 12 prevents the respective pattern tree 2 continues to rotate, even if no pattern thread 15 is consumed more. This prevents the tension in the pattern threads from dropping below a permissible value.

Claims (15)

Pattern tree arrangement (1) for a knitting machine with at least one pattern tree (2) which is rotatably mounted in a frame and on which at least one pattern thread (15) is wound, which is guided by a thread take-off arrangement, characterized in that the pattern tree (2) a slip drive (5). Pattern tree arrangement according to claim 1, characterized in that the slip drive (5) has a moving element (7) which acts with a frictional engagement on the pattern tree (2). Pattern tree arrangement according to claim 2, characterized in that the moving element (7) acts on the circumference (8) of the pattern tree (2). Pattern tree arrangement according to claim 2 or 3, characterized in that the moving element (7) forms a circulation (6). Pattern tree arrangement according to one of claims 2 to 4, characterized in that the moving element is designed as a brush belt (7). Pattern tree arrangement according to one of claims 2 to 5, characterized in that a plurality of pattern trees (2) are provided and the moving element (7) acts on a plurality of pattern trees (2). Pattern tree arrangement according to claim 6, characterized in that a plurality of pattern trees (2) are arranged in one plane and the moving element (7) is guided substantially rectilinearly over the pattern trees (2) arranged in the plane. Pattern tree arrangement according to claim 7, characterized in that pattern trees (2) are arranged in several planes, wherein in each plane a moving element (7) is arranged and the moving elements have a common drive (28). Pattern tree arrangement according to claim 7, characterized in that pattern trees (2) are arranged in several planes, wherein the moving element (7) drives pattern trees (2) in several planes. Pattern tree arrangement according to one of claims 1 to 9, characterized in that the pattern tree (2) has a controllable braking device (12). Pattern tree arrangement according to one of claims 1 to 10, characterized in that the thread withdrawal arrangement comprises a thread store (16). Pattern tree arrangement according to claim 11, characterized in that the thread store (16) has switching means (21, 22) for actuating the braking device (12). A pattern tree arrangement according to claim 12, characterized in that the switching means (21, 22) comprises a first sensor (21) indicating a filled state of the thread store (16) and a second sensor (22) having a deflated state of the thread store (16 ), wherein the first sensor (21) triggers an activation of the braking device (12) and the second sensor (22) terminates the activation of the braking device (12). Pattern tree arrangement according to claim 13, characterized in that the sensors (21, 22) are designed as non-contact sensors. Pattern tree arrangement according to one of claims 11 to 14, characterized in that the thread store (16) has a weight-loaded and vertically movable thread guide.

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