Textiles: manufacturing – Warp preparing or handling – With means responsive to sensed condition
Reexamination Certificate
1999-05-04
2001-03-06
Vanatta, Amy B. (Department: 3741)
Textiles: manufacturing
Warp preparing or handling
With means responsive to sensed condition
C028S196000, C028S199000
Reexamination Certificate
active
06195856
ABSTRACT:
This invention relates to a method for warping with a cone sectional warper that winds up the threads in bands on a warping drum, in which a support for a thread guide comb is displaced parallel to the warping drum by a forward feed drive, corresponding to the increasing thickness of the wind and predetermined warping data, with the first band being sensed during a measurement phase by a roll under contact pressure and with the sensed displacement travel being recorded as a function of the number of rotations of the warping drum, and with the roll being drawn back and pressing on the wind lap after the measurement phase upon further winding in accordance with a mean value obtained during the measurement phase.
In warping, a number of threads passing through the thread guide comb and guided by it are wound in bands on the warping drum that has a supporting cone. The first band of threads is wound up with a parallelogram cross section determined by the cone of the drum. The second band is then likewise wound up with a parallelogram cross section using the supporting action of the first band. Corresponding processes are repeated for the following bands of threads until the entire thread warp is wound up. The buildup of all of the bands of threads depends strongly on the properties of the threads to be wound up, for example on their capillarity, coloring, twist, spinning method, etc. Hard or soft wind laps are produced during the winding. For example, if the first band has too soft a wind structure, then the second band is worked into the flank of the first band, and consequently it does not grow high enough. Its warp length is shorter than that of the first band. If the wind lap structure of the first band is too hard, the second band becomes higher since the space for the second band has become smaller because of the swelling out of the first band. The warp length is then larger than that of the first band. Either of these leads to uneven distorted and patterned fabrics that accordingly are defective.
DE 26 31 573 C3 discloses a method with the process steps mentioned initially, in which the measurement made under pressure is accomplished during the measurement phase. The first band is then to be copied under the same pressure and all of the other bands are to be copied under pressure.
DE 34 32 276 A1 discloses a warping method in which a forward feed drive is controlled by a theoretically computed feed input to a processor. At the beginning of the first warp band, a measurement phase is completed, after which the wind lap formed is checked and compared with respect to its target state with the data stored in the processor. If necessary the warp slide length and the program stored in the processor are corrected, and if needed also with a second measurement phase. The first band is then warped completely and the forward feed motions during the warping of all of the following bands are then controlled as a function of those during the warping of the entire first band. Any required correction is made with the assistance of a sensor that is impacted by the roll and detects the roll position.
In both of the methods described above, there is no monitoring during the copying of the first band of whether the lap buildup is correct. Instead, the measurement phase has to be set up and performed so that error-free warps can be wound.
With this in mind, the underlying purpose of the invention is to improve a method with the features mentioned initially so that control of the lap buildup is still possible also during the copying of at least the first band.
This problem is solved by continuously monitoring by measurement the pressure of the roll on the lap during the measurement phase and/or during the further winding and/or copying and by making a correction of the support forward feed in case the monitored result differs from a predetermined set value.
Such a method makes it still possible to intervene in the buildup of the wind lap during the copying also. If the effective prevailing pressure does not correspond to the target pressure considering tolerance thresholds, then a reaction can be triggered that consists, for example, of a correction of the support forward feed. The support feed can therefore be reduced or interrupted or enlarged. This results in a reduced or increased growth of wind lap thickness, so that the wind lap buildup can still be smoothed out correctively even during the copying. Complete levelling of the pressure of the roll is possible during the entire warp buildup. As a consequence it is possible to exclude influences that cannot be detected during one measurement phase or even several measurement phases, for example the increase of thread tension from decreasing thread supply of the bobbins of the creel, or inaccurate input parameters whose deviations lead to a multiplication effect with lengthening warps.
The method described with respect to the measurement phase can be carried out so that the measurement phase is started with a set pressure chosen as a function of characteristics of the threads to be wound up. The winding process is adapted to the properties of the threads to be wound up, which are determined, for example, by the number of capillaries, the coloration, by the twist, or by the spinning process. This adaptation is important because even small deviations of this item-specific pressure setting lead to errors when taking the average that is obtained based on the recorded values of measurements during the measurement phase. Such errors can also have considerable effects because the long warp lengths bring about a corresponding multiplication effect.
However, the method described with regard to the measurement phase can also be implemented by determining a forward feed for the measurement phase whose magnitude is selected based on characteristics of the threads to be wound up. Such a determination of the forward feed that is thus calculated leads to a relative displacement of the warping drum with consideration not only of the cone angle but also additionally with consideration of the characteristics of the threads to be wound up. Such a method is particularly necessary when the pressure of the roll is to be practically zero during the measurement phase, or monitoring by measurement occurs only when copying. The use of a calculated forward feed during the measurement phase, however, can also be used as a supplement to monitoring the pressure of the roll on the wind lap during the measurement phase, with the calculated feed being modified in the measurement phase by means of the pressure sensor, so that after the measurement phase a correct forward feed again arises.
It is advantageous for the entire warp wind to carry out the method so that the correction of the support feed also occurs during the copying from bands following the first band. This causes warped bands distant from the cone also to be symmetrical with the lap buildup of the first band.
The method can be carried out so that the correction of the support forward feed occurs distributed stepwise over the turn of the drum in case of a pressure increase or decrease. This makes it possible to have corresponding control of the wind lap buildup, namely in the sense of smoothing over the circumference. For example, it is possible not to have to eliminate large pressure increases suddenly. Sudden pressure increases in the sense of pressure peaks occur, for example, in the area where the threads are hung on the cone drum. To some extent this is also the case when the hang points are embedded in the cone drum.
It may also be beneficial to carry out the method in such a way that brief pressure changes occurring during the measurement phase and/or during the copying are not taken into consideration when taking the average and/or when monitoring the pressure. In case of such brief pressure changes it can be assumed that no serious changes of the wind lap buildup will occur. Therefore, if pressure changes that occur do not go beyond a given length of time, no correction is made of the support forward feed
Pandiscio & Pandiscio
Sucker-Muller-Hacoba GmbH & Co.
Vanatta Amy B.
LandOfFree
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