Method for operating a spindle of a two-for-one twisting or cabling machine

1. A method for operating a spindle ( 2 ) of a two-for-one twisting or cabling machine, which comprises an adjustable balloon-yarn guide-eye ( 9 ), characterized in that, for the operation of the spindle ( 2 ) under production conditions, the balloon-yarn-guide-eye ( 9 ) is adjusted, on the basis of a measured value (i) which is provided by a unit which monitors energy consumption of a spindle drive ( 3 ), the measured value (i) correlating with the energy consumption of the spindle drive ( 3 ), to a first operating position (AP 1 ) in which a position-dependent minimum of the energy consumption of the spindle drive ( 3 ) is reached.

2. The method according to claim 1 , characterized in that the respective first operating position (AP 1 ) of the balloon-yarn-guide-eye ( 9 ) to be approached dependent upon yarn-twisting parameters is determined in advance and can be called up for the yarn-twisting batch to be processed in order to control an adjustment drive ( 18 ) for the balloon-yarn-guide-eye ( 9 ).

3. The method according to claim 1 , characterized in that the first operating position (AP 1 ) of the balloon-yarn-guide-eye ( 9 ) to be approached dependent upon yarn-twisting parameters is adjusted via a control circuit ( 20 ) and fine-tuned during the operation of the spindle ( 2 ), wherein a measured value (i) correlating with the energy consumption of the spindle drive serves as control value.

4. The method according to claim 1 , characterized in that the current consumption of the spindle drive ( 3 ), the size of a yarn balloon (B) or the yarn tension of an outer yarn ( 5 ) forming the yarn balloon (B) serves as measured value (i) correlating with the energy consumption of the spindle ( 2 ).

5. The method according to claim 1 , characterized in that the yarn tension of the outer yarn ( 5 ) constituting the yarn balloon (B) is increased by means of a controllable yarn-tension influencing device ( 22 ) constituted as a yarn-supply unit or yarn brake in such a manner that, for the operation of the spindle ( 2 ), the yarn balloon (B) is reduced to a size at which it still does not yet contact a protective pot ( 19 ) surrounding a feed bobbin ( 15 ).

6. The method according to claim 5 , characterized in that, after the adjustment of the yarn tension by the controllable yarn-tension influencing device ( 22 ), the balloon-yarn-guide-eye ( 9 ) is moved back in the direction of the yarn course, with a further reduction of the energy consumption, to a second operating position (AP 2 ), at the overshooting of which the energy consumption of the spindle ( 2 ) rises again.

7. The method according to claim 6 , characterized in that the second operating position (AP 2 ) of the balloon-yarn-guide-eye ( 9 ) is determined in advance and can be called up for the yarn-twisting batch to be processed in order to control an adjustment drive ( 18 ) for the balloon-yarn-guide-eye ( 9 ).

8. The method according to claim 6 , characterized in that the balloon diameter (D 2 ) is measured at a plane which is disposed in the region of the upper edge with the largest external diameter of the protective pot ( 19 ) as the measured value (i) correlating with the energy consumption of the spindle drive.

9. The method according to claim 6 , characterized in that the balloon diameter (D 2 ) is measured at a plane which is disposed in the region of the largest diameter of the yarn balloon B as the measured value (i) correlating with the energy consumption of the spindle drive.