Winding – tensioning – or guiding – Tension control or brake – Supply controlled
Reexamination Certificate
2001-05-04
2003-01-28
Matecki, Kathy (Department: 3654)
Winding, tensioning, or guiding
Tension control or brake
Supply controlled
C242S131100, C242S15000R, C242S419900, C028S194000
Reexamination Certificate
active
06511011
ABSTRACT:
BACKGROUND
The invention relates to a process for the operation of a bobbin creel for a winding system. With such a process, the best possible tension compensation of all the threads on a bobbin creel is striven for, because the different running lengths of the threads between the winding heads and the winding machine and the thread guide connected to them can, without the appropriate tension compensation may lead to different thread tension values. The consequence of this would be an unequal winding density.
From EP-A 319 477 a device is known for the tension compensation of the threads on a bobbin creel, with which, by means of a common control rod, the thread brakes (yarn tensioning devices) of the vertical rows of winding heads can be subjected to different force values. The control rod is activated by drive motors, which receive actuating signals from a processor. In this situation, the actual value of the thread tension of a whole thread bundle is measured by means of a measurement roller shortly before winding. It is not possible in this situation to take account of the thread tension of individual threads or individual groups of threads.
DE-A 195 46 473 discloses a process for the control of winding devices for yarn sheets. In this case too, measurement of the tension of the thread bundle is effected shortly before winding, in order to exert an effect on the tension of the threads on the bobbin creel by way of means which are not represented in any greater detail. With the aid of a measurement carriage which is capable of being moved transversely over the thread bundle, however, the sequential tension measurement of individual threads at a predetermined time interval is possible. From this a mean tension value is formed, in accordance with which the common tension of all the threads is effected. With this process, an individual control of individual threads or individually groups of threads can hardly be achieved, because it is not possible to scan each thread simultaneously. Further disadvantages of this process are that measurement at intervals is too slow with the winding speeds used today and, in addition, the thread being measured in each case is subjected to mechanical stress by the measuring means, which has the effect of changing the individual tension of a thread.
DE-A 44 18 729 likewise relates to a device for controlling the thread tension on a bobbin creel. This device features a brake rotor for each bobbin creel directly at the winding head. A tension lever serves as the measurement sensor for the thread tension, said lever being imposed by the wound-up thread. At each bobbin holder a load-imposing device operating with fluid pressure engages on the tension lever, whereby the fluid pressure is adjustable in common for all load-imposition devices. The individual control of the thread tension can therefore be overlaid by a general adjustment capability for all thread tensioners. One disadvantage of this arrangement lies in the fact, however, that the control circuit is restricted directly to the winding head. This arrangement is not well-suited for a bobbin creel with an overhead withdrawal. In addition, braking directly at the bobbin holder is not well-suited for all work processes, and the different running lengths of the threads between the winding head and the winding machine are not taken into account.
Finally, DE-U-296 08 169 discloses a winding device for threads of bobbin creels with which a measurement device is arranged for the determination of thread tension in threads, whereby the central adjustment of preliminary twisting rails allocated to the winding heads can be controlled in accordance with the measurement result. The measuring device consists of individual pressure measuring strips, which in each case support a plurality of threads. Accordingly, monitoring of the tension in individual threads is likewise not possible, apart from the fact that the pressure measurement strips in each case can only be imposed on the outermost threads of a thread bundle.
It would however be generally desirable, on a bobbin creel with different generic types of threads, e.g. different yarn qualities, yarn thicknesses, or yarn colors, to adapt the thread tension in each case to the individual thread generic types. It has hitherto not been possible at all to allow for individual consideration of yarn types.
SUMMARY OF THE INVENTION
The problem of the invention is therefore of creating a process of the type described in the preamble, which by simple means will allow for the optimum and versatile application of control of the overall winding process. In this situation, it is also intended that modern electronic means should be capable of being used, with low energy consumption. The creel control should be capable of adaptation to as many different operational conditions as possible. This problem is resolved according to the invention by a process described below.
By means of the sustained measurement of the actual value of the thread tension on each thread, the tension behavior of the threads on the entire creel can be acquired with minimal time delay. Measurement is effected in this situation in the area between leaving the creel and winding up on the winding machine, by means of which it can be assured that the different running lengths and deflections of the threads is taken into account. The control process can be designed individually for single threads or for groups of threads, as a result of which the creel can be put to versatile use. The mechanical function and arrangement of the thread brakes plays only a subordinate role in this situation. By means of this process, thread influences can be compensated for, such as different thread thicknesses, thread structure, other material influences and influences at the unwinding point in the bobbin creel.
According to the process according to the invention, each individual thread brake is activated by a drive motor allocated to it. This is possible without further ado with the economically-priced miniaturized drive units available today.
It is also possible to specify, with a thread group with the same material characteristics, the same thread tension specified value for each thread, and to match the measured actual thread tension values within the thread group to the predetermined thread tension specified value, by controlling the thread tension.
Further process advantages can be achieved if the threads are subjected to an additional braking force in the direction of run of the thread, before each thread brake, at least one preliminary tensioning device, said braking force being permanently set as a basic value, or which is set as a function of the measured actual value.
Depending on the material properties, such as quality, twisting, strength, and heel inclination etc. of the threads, different preliminary tensioning devices must be used in order to guarantee trouble-free withdrawal of the threads. Preliminary tensioning devices on a twist basis, such as eyelet preliminary tensioning devices, crepe preliminary tensioning devices, etc., can be adjusted individually or rail by rail by a drive motor, in order to obtain optimum thread withdrawal.
It is also possible for the different running lengths of the threads or thread groups (creel length compensation) to be compensated for exclusively with the aid of the preliminary tension devices. In this way the downstream thread brakes will be relieved of this mandatorily required compensation task, and they can then develop their full degree of efficiency with regard to their braking force.
In addition to this, preliminary tensioning devices of the type referred to heretofore can also be used to increase the thread tension before the intake into the thread brakes, whereby the thread tension can be adjusted in common with the thread brake individually or group by group. These preliminary tensioning devices can also be used as individual means for the distribution of the tension, however. In this situation, no additional thread brakes are required, which is economically ver
Bollen Manfred
Häne Stefan
Spari Anton
Zeller Hans-Peter
Benninger AG
Matecki Kathy
Pham Minh-Chau
Shoemaker and Mattare
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